Perovskite interface material

Abstract

The present disclosure relates to a device comprising: a) a three-dimensional perovskite compound layer; and b) a capping material layer including a capping material and disposed on the three-dimensional perovskite compound layer. The invention also relates to a method for preparing the device and a use of the device. Preferably, the capping material is a compound having the formula (A2) 2M (X2) 4, (A2) 2 (A1) M2 (X2) 7, (A2) mMn (X2) 3n + m, or any mixture thereof, and is preferably substantially free of Pb < 2 + > or Sn < 2 + >.

Description

Technical Field

[0001] The present invention relates to a device comprising a perovskite compound layer and a covering material layer, a method for preparing the device and uses of the device. Background Art

[0002] Perovskite solar cells (PSCs) have achieved certified power conversion efficiencies (PCEs) exceeding 25%, comparable to commercial silicon solar cells. However, the operational stability of PSCs still lags behind that of conventional silicon solar cells, severely limiting their commercialization potential.

[0003] Bilayer three-dimensional (3D) / low-dimensional (LD) perovskite solar cell (PSC) architecture has recently emerged as a promising approach to address the trade-off between photovoltaic performance and operational stability.

[0004] The overlying LD capping layer plays a crucial role not only in surface passivation but also in heterostructure construction and environmental stress tolerance. The most common LD capping materials are a class of halometalates, such as the popular two-dimensional (2D) Ruddlesden-Popper (RP) perovskites, which have the general formula A2MX4, where A is a bulky ammonium cation, M is a metal cation, and X is a halide anion. LD materials capping the 3D perovskite layer not only passivate the 3D perovskite defects but also protect the 3D perovskite from environmental stressors such as moisture, oxygen, light, and heat.

[0005] The widely used fabrication process for LD capping is to deposit bulk ammonium halide, such as phenylethylammonium iodide (PEAI), on 3D perovskite, followed by a cation exchange reaction, which is called the semi-precursor (HP) method. The metal cations of LD capping materials are limited to Pb 2+ / Sn 2+ , and since it is derived from the underlying 3D perovskite, it is almost irreplaceable under current methods. Therefore, the most common strategy in the design of new LD capping materials is to modify the bulky cations at the A site. Although interesting solid-state in-plane growth methods have recently been demonstrated to be particularly well controllable for 2DBA2PbI4 (BA = butylamine) on 3D perovskites, the inherent weak solid-state interactions / reactions and high pressure (60MPa) requirements may limit their applicability to LD materials with different metal cations from the underlying 3D perovskite layer. To date, tuning the metal cations of LD capping materials remains an unsolved problem, and the research on Pb 2+ / Sn 2+ Restrictions continue to raise environmental concerns.

[0006] Therefore, there is a need to provide a device that overcomes or at least alleviates one or more of the above-mentioned disadvantages. SUMMARY OF THE INVENTION

[0008] In one aspect, there is provided a device comprising:

[0009] a) A three-dimensional perovskite compound layer comprising a 1 )B(X 1 )3 three-dimensional perovskite compound, wherein:

[0010] A 1 At least one ion selected from one or more elements of Group 1 of the Periodic Table, having R 1 -(NH x ) y + Organic cations of the structure and any mixture thereof, wherein, as long as the valence permits, R 1 is CH or alkyl, x is 2 or 3, and y is 1 or 2;

[0011] B is at least one ion of one or more elements of Group 14 of the Periodic Table of the Elements or any mixture thereof; and

[0012] X 1 is a halide ion or any mixture thereof;

[0013] b) a covering material layer comprising a covering material, wherein the covering material layer is disposed on the three-dimensional perovskite compound layer, wherein the covering material is selected from the group consisting of 2 )2M(X 2 )4、(A 2 )2(A 1 )M2(X 2 )7、(A 2 ) m M n (X 2 ) 3n+m or any mixture thereof; wherein:

[0014] A 2 Is with R 2 -NH a + The ammonium cation of the structure, where R 2 is an optionally substituted C4-C 12 Alkyl, optionally substituted C3-C 12 cycloalkyl, optionally substituted arylalkyl, or any mixture thereof;

[0015] M is at least one ion of one or more elements from Group 2, Group 3, Group 7, Group 8, Group 9, Group 10, Group 11, Group 12, Group 13 or Group 15 of the Periodic Table of the Elements, or any mixture thereof;

[0016] X 2 is a halide ion or any mixture thereof;

[0017] m is an integer 1, 2, 3, 4 or 5;

[0018] n is an integer of 1 or 2; and

[0019] a is 0 or an integer of 1, 2 or 3.

[0020] Advantageously, in the device defined above, the metal present in the capping material may be the same as or different from the metal present in the three-dimensional perovskite compound.

[0021] Advantageously, the device may include a capping material that not only passivates defects in the three-dimensional perovskite compound but also protects the three-dimensional perovskite compound from environmental stressors such as moisture, oxygen, light, and heat. More advantageously, the capping material layer of the device defined above may induce more robust surface passivation for the three-dimensional perovskite compound and may form a stronger 3D / LD nN homo-heterojunction, thereby more significantly suppressing charge recombination and enhancing the built-in potential.

[0022] The device defined above can have an inverted structure (or pin-type architecture) and can achieve a power conversion efficiency (PCE) as high as 24.1%, with a corresponding certified PCE of 23.25%. The device can also advantageously have enhanced stability, retaining 94.5% of the initial PCE after operating for more than 1000 hours at the maximum power point (MPP) under conditions of an effective irradiance equivalent to one sun.

[0023] In another aspect, there is provided a method of preparing a device as defined above, comprising the steps of:

[0024] i) providing a three-dimensional perovskite compound layer comprising a compound having the formula (A 1 )B(X 1 )3 three-dimensional perovskite compound, wherein:

[0025] A 1 At least one ion selected from one or more elements of Group 1 of the Periodic Table, having R 1 -(NH x ) y + Organic cations of the structure and any mixture thereof, wherein, as long as the valence permits, R 1 is CH or alkyl, x is 2 or 3, and y is 1 or 2;

[0026] B is at least one ion of one or more elements of Group 14 of the Periodic Table of the Elements or any mixture thereof; and

[0027] X1 is a halide ion or any mixture thereof;

[0028] ii) having the formula M(X 2 ) z The metal halide and the metal halide having the formula (A 2 )(X 2 ) ammonium halide is mixed in a solvent to form a covering material solution, wherein

[0029] A 2 Is with R 2 -NH a + The ammonium cation of the structure, where R 2 is an optionally substituted C4-C 12 Alkyl, optionally substituted C3-C 12 cycloalkyl, optionally substituted arylalkyl, or any mixture thereof;

[0030] M is at least one ion of one or more elements from Group 2, Group 3, Group 7, Group 8, Group 9, Group 10, Group 11, Group 12, Group 13 or Group 15 of the Periodic Table of the Elements, or any mixture thereof;

[0031] X 2 is a halide ion or any mixture thereof;

[0032] a is 0 or the integer 1, 2 or 3; and

[0033] z is 2 or 3; and

[0034] iii) applying a covering material solution onto the three-dimensional perovskite compound layer to form a covering material layer comprising a covering material, wherein the covering material is selected from the group consisting of: 2 )2M(X 2 )4、(A 2 )2(A 1 )M2(X 2 )7、(A 2 ) m M n (X 2 ) 3n+m a compound or any mixture thereof;

[0035] wherein m is an integer of 1, 2, 3, 4 or 5; and

[0036] n is an integer of 1 or 2.

[0037] Advantageously, the method defined herein requires that a capping material solution comprising a metal halide and an ammonium halide be applied to the three-dimensional perovskite compound. Advantageously, this enables easier synthetic control of the capping material layer, thereby applying only the ammonium halide to the three-dimensional perovskite compound, compared to the conventional semi-precursor (HP) method for preparing the device. Due to the presence of the metal halide in the capping material solution, the formation of the capping material does not rely on the upward diffusion of the metal from the underlying three-dimensional perovskite layer. Therefore, the method defined herein provides unprecedented opportunities for preparing a variety of capping materials on the three-dimensional perovskite compound, including capping materials that may not contain Pb.

[0038] Advantageously, because this method can allow the use of a variety of metals, even lead-free, in the capping material, it can allow the fabrication of an expanded range of efficient and stable 3D / LD PSCs that were previously not possible via conventional HP methods.

[0039] In another aspect, the present invention also provides the use of the device defined above in an optoelectronic device, a photovoltaic cell, a solar cell, a light emitting diode (LED), a laser or a photodetector, a radiation detector, a memristor, a spintronic device, a phototransistor, a transistor, a light emitting transistor (LET) or a field effect transistor (FET).

[0040] definition

[0041] As used herein, the following words and terms have the meanings indicated:

[0042] "Alkyl" as a group or part of a group refers to a straight-chain or branched aliphatic hydrocarbon group, preferably C1-C 12 Alkyl, more preferably C1-C 10 Alkyl, most preferably C1-C6 alkyl, unless otherwise specified. Examples of suitable straight chain and branched C1-C6 alkyl substituents include methyl, ethyl, n-propyl, 2-propyl, n-butyl, sec-butyl, tert-butyl, hexyl, etc. The group can be a terminal group or a bridging group.

[0043] "Cycloalkyl" refers to a saturated monocyclic or fused or spirocyclic carbon ring, preferably containing 3-12 carbon atoms per ring, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc., unless otherwise specified. It includes monocyclic systems such as cyclopropyl and cyclohexyl, bicyclic systems such as decalin, and polycyclic systems such as adamantane. Cycloalkyl is generally C3-C 12 Alkyl. This group can be a terminal group or a bridging group.

[0044] "Arylalkyl" refers to an aryl-alkyl group in which the aryl and alkyl portions are as defined herein. Preferred arylalkyl groups contain C 1-12Alkyl moiety. Exemplary arylalkyl groups include benzyl, phenethyl, 1-naphthylmethyl, and 2-naphthylmethyl. This group can be a terminal group or a bridging group. If the group is a terminal group, it is bonded to the rest of the molecule through the alkyl group.

[0045] As used herein, the term "optionally substituted" means that the group to which the term refers may be unsubstituted or substituted with one or more groups independently selected from the group consisting of acyl, alkyl, alkenyl, alkynyl, thiol, thioalkyl, cycloalkyl, cycloalkylalkyl, cycloalkenyl, cycloalkylalkenyl, heterocycloalkyl, cycloalkylheteroalkyl, cycloalkoxy, cycloalkenyloxy, cycloamino, halogen, carboxyl, carboxylate, haloalkyl, haloalkynyl, alkynyloxy, heteroalkyl, heteroalkenyl, heteroalkynyl, heteroalkoxy, hydroxy, hydroxyalkyl, alkoxy, thioalkoxy, alkenyloxy, haloalkoxy, haloalkenyl, haloalkynyl, haloalkenyloxy, nitro, amino, nitroalkyl, nitroalkenyl, nitroalkynyl, nitroheterocyclyl, alkylamino, dialkylamino, alkenylamine, aminoalkyl, alkynylamino, acyl, alkoxy, alkoxyalkyl, alkoxyaryl, alkoxycarbonyl, alkoxycycloalkyl, alkoxyheteroaryl, alkoxyheterocycloalkyl , alkenoyl, alkynyl, amide, diamide, acyloxy, alkylsulfonyloxy, heterocycle, heterocyclealkenyl, heterocyclealkyl, heterocyclealkylalkyl, heterocyclealkylalkenyl, heterocyclealkylalkenyl, heterocyclealkylheteroalkyl, heterocyclealkoxy, heterocyclealkenyloxy, heterocycleoxy, heterocycleamino, halogenated heterocyclealkyl, alkylsulfinyl, alkylsulfonyl, alkylthiooxy, alkylcarbonyloxy, alkylthio, acylthio, aminosulfonyl, phosphoryl and phosphinyl groups, alkyl), -C(O)NH(alkyl) and -C(O)N(alkyl).

[0046] A "bond" is a connection between atoms in a compound or molecule. A bond can be single, double, or triple.

[0047] The word "substantially" does not exclude "completely", for example, a composition that is "substantially free" of Y may be completely free of Y. If necessary, the word "substantially" may be omitted from the definition of the invention.

[0048] Unless otherwise stated, the terms "include" and "comprising" and their grammatical variations are intended to represent "open" or "inclusive" language such that they include not only the listed elements but also allow for additional, non-listed elements.

[0049] As used herein, the term "about" in the context of a formulation component concentration typically refers to ±5% of the stated value, more typically ±4% of the stated value, more typically ±3% of the stated value, more typically ±2% of the stated value, even more typically ±1% of the stated value, and even more typically ±0.5% of the stated value.

[0050] Throughout this disclosure, certain embodiments may be disclosed in the form of ranges. It should be understood that descriptions in range format are for convenience and brevity only and should not be considered as rigid limitations on the disclosed ranges. Therefore, descriptions of ranges should be considered to have explicitly disclosed all possible subranges within that range and each numerical value within that range. For example, descriptions of ranges such as 1-6 should be considered to have explicitly disclosed subranges such as 1-3, 1-4, 1-5, 2-4, 2-6, 3-6, and each numerical value within that range, such as 1, 2, 3, 4, 5, and 6. This applies regardless of the width of the range.

[0051] Certain embodiments may be described broadly and generically herein. Narrower categories and sub-generic groupings falling within the generic disclosure each also form part of this disclosure. This includes generic descriptions of embodiments with proviso or negative limitations that delete any subject matter from the generic concept, regardless of whether the deleted material is specifically recited herein.

[0052] Detailed description of optional implementation plans

[0053] A device is provided, comprising:

[0054] a) A three-dimensional perovskite compound layer comprising a 1 )B(X 1 )3 three-dimensional perovskite compound, wherein:

[0055] A 1 At least one ion of an element from Group 1 of the Periodic Table of Elements having R 1 -(NH x ) y + Organic cations of the structure and any mixture thereof, wherein, as long as the valence permits, R 1 can be CH or alkyl, x can be 2 or 3, and y can be 1 or 2;

[0056] B may be at least one ion of one or more elements of Group 14 of the Periodic Table of Elements or any mixture thereof; and

[0057] X 1 It can be a halide ion or any mixture thereof;

[0058] b) a covering material layer, comprising a covering material, wherein the covering material layer is disposed on the three-dimensional perovskite compound layer, wherein the covering material can be selected from the group consisting of 2 )2M(X 2 )4、(A 2 )2(A 1 )M2(X 2 )7、(A 2 ) m M n (X 2 ) 3n+m or any mixture thereof; wherein:

[0059] A 2 Can be R 2 -NH a + The ammonium cation of the structure, where R 2 It may be an optionally substituted C4-C 12 Alkyl, optionally substituted C3-C 12 cycloalkyl, optionally substituted arylalkyl, or any mixture thereof;

[0060] M may be at least one ion of one or more elements of Group 2, Group 3, Group 7, Group 8, Group 9, Group 10, Group 11, Group 12, Group 13 or Group 15 of the Periodic Table of Elements, or any mixture thereof;

[0061] X 2 It can be a halide ion or any mixture thereof;

[0062] m can be an integer of 1, 2, 3, 4 or 5;

[0063] n can be an integer of 1 or 2; and

[0064] a can be 0 or an integer of 1, 2 or 3.

[0065] A 1 Can be selected from CH3NH3 + 、CH(NH2)2 + 、Cs + , Rb + and any mixtures thereof.

[0066] B can be selected from Pb 2+ 、Sn 2+ 、Ge 2+ and any mixtures thereof.

[0067] X 1 Can be selected from I - Br - 、Cl - 、F -and any mixtures thereof.

[0068] Three-dimensional perovskite compounds can have the structure Cs 0.15 FA 0.85 PbI 2.8 Cl 0.2 , Rb 0.05 Cs 0.10 FA 0.85 PbI 2.8 Cl 0.2 or Cs 0.05 (FA 0.83 MA 0.17 ) 0.95 Pb(I 0.83 Br 0.17 )3, wherein MA can be CH3NH3 + , and FA can be CH(NH2)2 + .

[0069] Optionally substituted C4-C 12 Alkyl, optionally substituted C3-C 12 The cycloalkyl group or the optionally substituted arylalkyl group may each independently be substituted or unsubstituted.

[0070] If substituted, then C4-C 12 Alkyl, C3-C 12 The cycloalkyl or arylalkyl groups may each independently be substituted with a group selected from -OH, -SH, -COOH and any mixture thereof.

[0071] A 2 The ion may be selected from phenylethylammonium (PEA) ion, n-butylammonium (BA) ion, isobutylammonium ion, benzylammonium (PMA) ion, naphthylmethylammonium (NMA) ion, and any mixture thereof.

[0072] M can be selected from Zn 2+ , Pb 2+ 、Co 2+ 、Mn 2+ 、Cu 2+ 、Sb 3+ 、Bi 3+ 、Al 3+ and any mixtures thereof.

[0073] X 2 Can be selected from Cl - Br - , I - 、F - and any mixtures thereof.

[0074] The covering material layer may have a β-K2SO4 type, β-K2PO3F type, cubic, orthorhombic or tetragonal single crystal structure.

[0075] The capping material layer may have a perovskite single crystal structure. The cubic structure may have a space group Pm3m numbered 221. The orthorhombic structure may have a space group Pnma numbered 62, or Amm2 numbered 68. The tetragonal structure may have a space group I4 / mcm numbered 140, or P4mm numbered 99.

[0076] The covering material layer may be substantially free of Pb 2+ or Sn 2+ .

[0077] The covering material layer may be zero-dimensional, one-dimensional, two-dimensional, or three-dimensional.

[0078] The three-dimensional perovskite compound layer and the capping material layer can be annealed independently. Advantageously, annealing can improve the performance of each layer by increasing crystallinity, toughness, and machinability.

[0079] The metal present in the capping material (M) may be different from the metal present in the three-dimensional perovskite compound (B).

[0080] For the purposes of this disclosure, the three-dimensional perovskite compound layer may be referred to as a “three-dimensional layer” or “3D layer,” and the capping material layer may be referred to as a “low-dimensional layer” or “LD layer.”

[0081] The device may further include a hole transport layer comprising a hole transport material, wherein the three-dimensional perovskite compound layer may be disposed on the hole transport layer.

[0082] The hole transport material may be selected from poly(triarylamine) (PTAA), poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), (2-(9H-carbazol-9-yl)ethyl)phosphoric acid (2PACZ), [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphoric acid (MeO-2PACZ), [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphoric acid (Me-4PACz), (2-(3,6-dimethyl-9H-carbazol-9-yl)ethyl)phosphoric acid (Me-2PACz), NiO, CuSCN, CuO, and any mixture thereof.

[0083] The device may further comprise an electrode, wherein the hole transport layer may be disposed on the electrode.

[0084] The electrode may be selected from indium tin oxide (ITO), fluorine doped tin oxide (FTO), and any mixture thereof.

[0085] The device may further include an electron transport layer including an electron transport material and disposed on the capping material layer.

[0086] The electron transport material can be selected from C 60 / Bathocuproin ([6,6]-phenyl-C61-butyric acid methyl ester, BCP), 4-[3′-phenyl-3′H-cyclopropane[1,9](C 60 -I h )[5,6]fullerene-3′-yl]butyric acid methyl ester (PC61BM), (6,6)-phenyl C71 butyric acid methyl ester (PC71BM), 1',1",4',4"-tetrahydro-di[1,4]methylnaphtho[5,6]fullerene-C60 (ICBA), tin (IV) oxide, zinc oxide and any mixture thereof.

[0087] The device may further include a counter electrode disposed on the electron transport layer.

[0088] The counter electrode may comprise an element selected from the group consisting of gold, silver, platinum, aluminum, copper, carbon, and any mixtures thereof.

[0089] The electron transport layer, the capping material layer, the three-dimensional perovskite compound layer, and the hole transport layer may independently be in the form of films.

[0090] The device may comprise the layers defined above in the following order:

[0091] - Counter electrode

[0092] -Electron transport layer

[0093] - Covering material layer

[0094] -3D perovskite layer

[0095] -Hole transport layer

[0096] -electrode

[0097] The device can have an inverted structure or a pin-type architecture.

[0098] The thickness of the counter electrode can be in the range of about 100 nm to about 200 nm, about 100 nm to about 120 nm, about 100 nm to about 140 nm, about 100 nm to about 160 nm, about 100 nm to about 180 nm, about 120 nm to about 140 nm, about 120 nm to about 160 nm, about 120 nm to about 180 nm, about 120 nm to about 200 nm, about 140 nm to about 160 nm, about 140 nm to about 180 nm, about 140 nm to about 200 nm, about 160 nm to about 180 nm, about 160 nm to about 200 nm, or about 180 nm to about 200 nm.

[0099] The thickness of the electron transport layer may be in a range of about 45 nm to about 75 nm, about 45 nm to about 60 nm, or about 60 nm to about 75 nm.

[0100] The thickness of the capping material layer may be in a range of about 15 nm to 25 nm, about 15 nm to about 20 nm, or about 20 nm to about 25 nm.

[0101] The thickness of the three-dimensional perovskite compound layer may be in a range of about 400 nm to about 700 nm, about 400 nm to about 500 nm, about 400 nm to about 600 nm, about 500 nm to about 600 nm, about 500 nm to about 700 nm, or about 600 nm to about 700 nm.

[0102] The thickness of the hole transport layer may be in a range from about 20 nm to about 80 nm, about 20 nm to about 40 nm, about 20 nm to about 60 nm, about 40 nm to about 60 nm, about 40 nm to about 80 nm, or about 60 nm to about 80 nm.

[0103] The thickness of the electrode may be in a range from about 150 nm to about 300 nm, about 150 nm to about 200 nm, about 150 nm to about 250 nm, about 200 nm to about 250 nm, about 250 nm to about 300 nm, or about 250 nm to about 300 nm.

[0104] The device can be an optoelectronic device, a photovoltaic cell, a solar cell, a light emitting diode (LED), a laser or a light detector, a radiation detector, a memristor, a spintronic device, a phototransistor, a transistor, a light emitting transistor (LET), or a field effect transistor (FET).

[0105] Also provided is a method for preparing the above device, the method comprising the following steps:

[0106] i) providing a three-dimensional perovskite compound layer comprising a compound having the formula (A 1 )B(X 1 )3 three-dimensional perovskite compound, wherein:

[0107] A 1 At least one ion of an element from Group 1 of the Periodic Table of Elements having R 1 -(NH x ) y + Organic cations of the structure and any mixture thereof, wherein, as long as the valence permits, R 1 can be CH or alkyl, x can be 2 or 3, and y can be 1 or 2;

[0108] B may be at least one ion of one or more elements of Group 14 of the Periodic Table of Elements or any mixture thereof; and

[0109] X 1 It can be a halide ion or any mixture thereof;

[0110] ii) having the formula M(X 2 ) z The metal halide and the metal halide having the formula (A 2 )(X 2 ) ammonium halide is mixed in a solvent to form a covering material solution, wherein

[0111] A 2 Can be R 2 -NH a + The ammonium cation of the structure, where R 2 It may be an optionally substituted C4-C 12 Alkyl, optionally substituted C3-C 12 cycloalkyl, optionally substituted arylalkyl, or any mixture thereof;

[0112] M may be at least one ion of one or more elements of Group 2, Group 3, Group 7, Group 8, Group 9, Group 10, Group 11, Group 12, Group 13 or Group 15 of the Periodic Table of Elements, or any mixture thereof;

[0113] X 2 It can be a halide ion or any mixture thereof;

[0114] a can be 0 or the integers 1, 2 or 3; and

[0115] z can be 2 or 3; and

[0116] iii) applying a covering material solution onto the three-dimensional perovskite compound layer to form a covering material layer comprising a covering material, wherein the covering material is selected from the group consisting of: 2 )2M(X 2 )4、(A 2 )2(A 1 )M2(X 2 )7、(A 2 ) m M n (X 2 ) 3n+m a compound or any mixture thereof;

[0117] Where m can be an integer of 1, 2, 3, 4 or 5; and

[0118] n can be an integer of 1 or 2.

[0119] With the formula M(X 2 ) z The metal halide can be selected from Pb(X 2 )2、Zn(X 2 )2、Sn(X 2 )2、Co(X 2 )2、Mn(X 2 )2、Cu(X 2 )2、Sb(X 2 )3、Bi(X 2 )3、Al(X 2 )3 and any mixture thereof.

[0120] With formula (A 2 )(X 2 ) can be selected from phenylethylammonium halide (PEA (X 2 ))、n-butylammonium halide (BA(X 2 ))、Isobutylammonium halide、Benzylammonium halide (PMA(X 2 ))、1-naphthylmethylammonium halide (NMA(X 2 )) and any mixture thereof.

[0121] The solvent may be selected from acetonitrile (ACN), acetone, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), methanol, tert-butanol, ethanol, isopropanol, tetrahydrofuran, methylamine, and any mixture thereof.

[0122] In the covering material solution, the 2 ) z The metal halide and the metal halide having the formula (A 2 )(X 2 ) can be present in a molar ratio ranging from about 1:1 to about 1:3, from about 1:1 to about 1:2, or from about 1:2 to about 1:3.

[0123] In the covering material solution, the 2 ) z The concentration of the metal halide in the solvent can be in the range of about 5 mM to about 50 mM, about 5 mM to about 15 mM, about 5 mM to about 30 mM, about 15 mM to about 30 mM, about 15 mM to about 50 mM, or about 30 mM to about 50 mM.

[0124] The applying step may include applying the capping material solution directly onto the three-dimensional perovskite compound layer.

[0125] The applying step may include spin coating, spray coating, or slit coating the covering material solution on the three-dimensional perovskite compound layer, or immersing the three-dimensional perovskite compound layer in the covering material solution.

[0126] The method may further include the step of annealing each of the capping material layer and the three-dimensional perovskite compound layer.

[0127] The method may further comprise the step of providing a hole transport layer comprising a hole transport material, wherein the three-dimensional perovskite compound layer may be disposed on the hole transport layer.

[0128] The method may further comprise the step of providing an electrode, wherein the hole transport layer is disposed on the electrode.

[0129] The method may further include the step of applying an electron transport layer comprising an electron transport material on the capping material layer.

[0130] The method may further comprise the step of applying a counter electrode on the electron transport layer.

[0131] Furthermore, the present invention provides the use of the device defined above in an optoelectronic device, a photovoltaic cell, a solar cell, a light emitting diode (LED), a laser or a photodetector, a radiation detector, a memristor, a spintronic device, a phototransistor, a transistor, a light emitting transistor (LET) or a field effect transistor (FET).

[0132] BRIEF DESCRIPTION OF THE DRAWINGS

[0133] The accompanying drawings illustrate the disclosed embodiments and are used to explain the principles of the disclosed embodiments. However, it should be understood that the accompanying drawings are only for illustration purposes and are not used to define the boundaries of the present disclosure.

[0134] Figure 1A

[0135] Figure 1A Schematic comparison of the FP method disclosed in this article and the conventional HP method in preparing 3D / LD stacked films.

[0136] Figure 1B

[0137] Figure 1B The crystal structures of 2D PEA2PbI4 and 0D PEA2ZnX4 (X=Cl / I) are shown.

[0138] Figure 1C

[0139] Figure 1C Figure 2 shows a series of X-ray diffraction (XRD) patterns of the pristine LD material. The vertical gray-shaded areas with numbers indicate the main peak positions of 0D PEA2ZnX4. The symbols (asterisks, #, and +) denote the main peak positions of PEAI, 2D PEA2PbI4, and quasi-2DPEA2FAPb2I7, respectively.

[0140] Figure 1D

[0141] Figure 1D It is a series of full-range XRD patterns of the original LD ​​materials (PEA2ZnCl4, PEA2ZnI2Cl2, PEA2ZnI4, PEA2FAPb2I7, PEA2PbI4 and PEAI).

[0142] Figure 1E

[0143] Figure 1E is the control Rb5Cs 10 and Rb5Cs 10 A series of XRD patterns of a 2D / LD stacked film. The numbered vertical gray shading and dashed vertical lines indicate the main peak positions of 0D PEA2ZnX4 and 3D perovskite, respectively. Symbols (asterisks, #, and +) denote the main peak positions of PEAI, 2D PEA2PbI4, and quasi-2DPEA2FAPb2I7, respectively.

[0144] Figure 1F

[0145] Figure 1F is the control Rb5Cs 10 and Rb5Cs 10 A series of full-range XRD patterns of the / LD stacked films.

[0146] Figure 1G

[0147] Figure 1G is the control Cs 15 and Cs 15 A series of XRD patterns of a 3D perovskite / LD stacked film. The vertical gray shading and dashed lines with numbers indicate the main peak positions of 0D PEA2ZnX4 and 3D perovskite, respectively. Symbols (asterisks, #, and +) indicate the main peak positions of PEAI, 2DPEA2PbI4, and quasi-2DPEA2FAPb2I7, respectively.

[0148] Figure 1H

[0149] Figure 1H is the control Cs 15 and Cs 15 A series of full-range XRD patterns of / LD stacked films.

[0150] Figure 2

[0151] Figure 2 A series of XRD patterns of pristine NMAI, (NMA)2PbI4, (NMA)2FAPb2I7 films, and 3D / NMAI and 3D / (NMA)2PbI4 stacked films.

[0152] Figure 3

[0153] Figure 3 is a series of XRD patterns of RbCl / PEA2ZnI2Cl2 stacked films and pristine RbCl, PEAI, and PEA2ZnI2Cl2 films.

[0154] Figure 4A

[0155] Figure 4A It is Rb5Cs 10 Fitting of low-angle XRD peaks for a PEA2PbI4 / PEA2PbI4 stacked film. Fitting is based on the Pearson VII function. A values ​​represent relative peak areas. Relative intensities are raw values ​​and were obtained under the same measurement conditions.

[0156] Figure 4B

[0157] Figure 4B It's Cs 16 Fitting of low-angle XRD peaks for a ZnI / PEA2ZnI4 stacked film. Fitting is based on a Gaussian function. A values ​​represent relative peak areas. Relative intensities are raw values ​​and were obtained under the same measurement conditions.

[0158] Figure 4C

[0159] Figure 4C It is Rb5Cs 10 Fitting of low-angle XRD peaks for a ZnI / PEA2ZnI4 stacked film. Fitting is based on a Gaussian function. A values ​​represent relative peak areas. Relative intensities are raw values ​​and were obtained under the same measurement conditions.

[0160] Figure 5A

[0161] Figure 5A UV-Vis spectra of PEA2PbI4 and PEA2FAPb2I7. The membranes were prepared using the precursor solution of Example 1 with the same metal ion concentration of 17 mM.

[0162] Figure 5B

[0163] Figure 5B UV-Vis spectra of PEA2ZnI4 and PEA2ZnI2Cl2. The membranes were prepared using the precursor solution of Example 1 with the same metal ion concentration of 17 mM.

[0164] Figure 5C

[0165] Figure 5C Involving control Rb5Cs 10 and Rb5Cs 10UV-visible spectra of Rb5Cs / LD stacked films based on relatively thin Rb5Cs 10 Relatively thin Rb5Cs 10 The membranes were prepared using the precursor solution of Example 1, but with a metal ion concentration of 0.1M.

[0166] Figure 6A

[0167] Figure 6A It is a schematic diagram of the geometric structure of grazing-incidence wide / small-angle X-ray scattering (GIWAXS / GISAXS) in the prior art.

[0168] Figure 6B

[0169] Figure 6B is a graphical representation of the GIWAXS and GISAXS scattering patterns of organic photovoltaic thin film samples in the prior art.

[0170] Figure 6C

[0171] Figure 6C The images shown show GIWAXS patterns (at Ψ = 0°, out-of-plane) of (a) control 3D and 3D / LD stacked films, (b) 3D / PEA1, (c) 3D / PEA2PbI3, (d) 3D / PEA2ZnI4, and (e) 3D / PEA2ZnI2Cl2. Labels are Pb-LD: quasi-2D PEA2FAPb2I7, Zn-LD: 0D PEA2ZnX4.

[0172] Figure 6D

[0173] Figure 6D is the control 3D (Cs 15 ) A series of GIWAXS and GISAXS images of the film at different Ψ angles. (a) GIWAX at Ψ = 0°, (b) in-plane GIWAX at Ψ = 90°, (c) in-plane and out-of-plane GISAXS at 90°, and (d) out-of-plane GISAXS at 180°.

[0174] Figure 6E

[0175] Figure 6E Figure 1 shows the GIWAXS and GISAXS images of the 3D / PEAI stacked film at different Ψ angles. (a) GIWAX at Ψ = 0°, (b) in-plane GIWAX at Ψ = 90°, (c) in-plane and out-of-plane GISAXS at 90°, and (d) out-of-plane GISAXS at 180°.

[0176] Figure 6F

[0177] Figure 6F Figure 3 shows the GIWAXS and GISAXS images of 3D / PEA2PbI4 stacked films at different Ψ angles. (a) GIWAX at Ψ = 0°, (b) in-plane GIWAX at Ψ = 90°, (c) in-plane and out-of-plane GISAXS at 90°, and (d) out-of-plane GISAXS at 180°.

[0178] Figure 6G

[0179] Figure 6G Figure 3 shows the GIWAXS and GISAXS images of 3D / PEA2ZnI4 stacked films at different Ψ angles. (a) GIWAX at Ψ = 0°, (b) in-plane GIWAX at Ψ = 90°, (c) in-plane and out-of-plane GISAXS at 90°, and (d) out-of-plane GISAXS at 180°.

[0180] Figure 6H

[0181] Figure 6H Figure 3 shows the GIWAXS and GISAXS images of 3D / PEA2ZnI2Cl2 stacked films at different Ψ angles. (a) GIWAX at Ψ = 0°, (b) in-plane GIWAX at Ψ = 90°, (c) in-plane and out-of-plane GISAXS at 90°, and (d) out-of-plane GISAXS at 180°.

[0182] Figure 7A

[0183] Figure 7A High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) image of the cross section of a FP-based 3D / PEA2ZnX4 PSC.

[0184] Figure 7B

[0185] Figure 7B Energy-dispersive X-ray spectroscopy (EDX) elemental map of Zn in the cross section of the FP-based 3D / PEA2ZnX4 PSC.

[0186] Figure 7C

[0187] Figure 7C yes Figure 7AThe EDX spectrum of region 1 is shown in Figure 1. A characteristic Zn Kα peak at 8.63 eV is visible in region 1, indicating the location of the Zn-LD (PEA2ZnX4) capping layer. No lattice fringes are observed in the Zn-LD layer (region 1), which may be due to the relatively low crystallinity of 0D PEA2ZnX4 and / or damage caused by the FIB during sample thin film preparation.

[0188] Figure 7D

[0189] Figure 7D yes Figure 7A EDX spectrum of region 2 is shown in FIG.

[0190] Figure 8A

[0191] Figure 8A Figure 1 shows the time-of-flight secondary ion mass spectrometry (ToF-SIMS) elemental depth profiles of control 3D PSCs. For clarity, the relative intensities of Pb, In, and Zn elements have been scaled up or down as indicated in the figure legend.

[0192] Figure 8B

[0193] Figure 8B Figure 1 shows the ToF-SIMS elemental depth profiles of control 3D / PEA2ZnX4 PSCs. For clarity, the relative intensities of Pb, In, and Zn elements have been scaled up or down as indicated in the figure legend.

[0194] Figure 9A

[0195] Figure 9A are scanning electron microscope (SEM) images of PEA2ZnX4 capping layers deposited on bare ITO glass substrates. Representative PEA2ZnX 4充分 Covered area and insufficiently covered area (bare ITO area). Scale bar represents 500 nm.

[0196] Figure 9B

[0197] Figure 9B EDX elemental map of C of a PEA2ZnX4 capping layer deposited on a bare ITO glass substrate. The scale bar represents 500 nm.

[0198] Figure 9C

[0199] Figure 9C Zn EDX elemental map of a PEA2ZnX4 capping layer deposited on a bare ITO glass substrate. The scale bar represents 500 nm.

[0200] Figure 10

[0201] Figure 10 is a series of SEM images, consisting of planar SEM images (a) to (e) and cross-sectional SEM images (f) to (i): (a) pristine 3D perovskite, (b) HP-based 3D / PEAI, (c) FP-based 3D / PEA2PbI4, (d) 3D / PEA2ZnI4, and (e) 3D / PEA2ZnI2Cl2 films; and (f) 3D / PEAI, (g) 3D / PEA2PbI4, (h) 3D / PEA2ZnI4, and (i) 3D / PEA2ZnI2Cl2 films. 3D perovskite is Rb5Cs 10 The scale bar represents 500 nm.

[0202] Figure 11A

[0203] Figure 11A Atomic force microscopy (AFM) images of Rb5Cs10 films. RMS refers to the root mean square roughness of the surface. The scale bar represents 2 μm.

[0204] Figure 11B

[0205] Figure 11B Atomic force microscopy (AFM) images of HP-based 3D / PEAI films. RMS refers to the root mean square roughness of the surface. Scale bar represents 2 μm.

[0206] Figure 11C

[0207] Figure 11C Atomic force microscopy (AFM) images of FP-based 3D / PEA2PbI4 films. RMS refers to the root mean square roughness of the surface. Scale bar represents 2 μm.

[0208] Figure 11D

[0209] Figure 11D Atomic force microscopy (AFM) images of 3D / PEA2ZnI4 films. RMS refers to the root mean square roughness of the surface. Scale bar represents 2 μm.

[0210] Figure 11E

[0211] Figure 11E Atomic force microscopy (AFM) images of 3D / PEA2ZnI2Cl2 films. RMS refers to the root mean square roughness of the surface. Scale bar represents 2 μm.

[0212] Figure 12A

[0213] Figure 12A Schematic diagram and cross-sectional SEM image of the disclosed 3D / LD PSC. Charge and terminal symbols represent photoinduced electrons / holes and the device anode / cathode, respectively. The LD capping material in the cross-sectional SEM image is PEA2ZnX4. Scale bar represents 200 nm.

[0214] Figure 12B

[0215] Figure 12B Figure 1 is a box-and-whisker plot of the statistical distribution of the open-circuit voltage (VOC) of PSCs without (control) or with capping materials made by HP or FP processes (25 independent devices of each type were used for statistics). The center dashed line, box, and whiskers represent the mean, 75th percentile (upper edge), 25th percentile (lower edge), and outliers, respectively.

[0216] Figure 12C

[0217] Figure 12C is the short-circuit current density (J) of PSCs without (control) or with capping materials made by HP or FP processes SC ) Box and whisker plot of the statistical distribution (25 independent devices of each type were used for statistics). The center dashed line, box, and whiskers represent the mean, 75th percentile (upper edge), 25th percentile (lower edge), and outliers, respectively.

[0218] Figure 12D

[0219] Figure 12D Figure 1 is a box-and-whisker plot of the fill factor (FF) distribution of PSCs without (control) or with capping materials fabricated by HP or FP processes (25 individual devices of each type were used for statistical analysis). The center dashed line, box, and whiskers represent the mean, 75th percentile (upper edge), 25th percentile (lower edge), and outliers, respectively.

[0220] Figure 12E

[0221] Figure 12E Figure 5 is a box and whisker plot of the power conversion efficiency (PCE) of PSCs without (control) or with capping materials made by HP or FP processes (25 independent devices of each type were used for statistics). The center dashed line, box, and whiskers represent the mean, 75th percentile (upper edge), 25th percentile (lower edge), and outliers, respectively.

[0222] Figure 13A

[0223] Figure 13AThe control 3D perovskite, 3D / PEAI and 3D / PEA2ZnX4 stacked films deposited on glass substrates were at 0.177 μJ cm -2 Pseudo-colored time-resolved photoluminescence (TRPL) images at 640 nm excitation under integrated fluence. The color scale represents the normalized PL intensity, ranging from 0 to 1. The pseudo-colored TRPL images of the 3D / PEAI and 3D / PEA2ZnX4 stacked films exhibit long tails (white regions) relative to the control 3D film, indicating a longer photoluminescence lifetime.

[0224] Figure 13B

[0225] Figure 13B is a plot of normalized photoluminescence versus decay time.

[0226] Figure 14A

[0227] Figure 14A A series of images showing the fluence-dependent TRPL of a control 3D perovskite film. (a) to (f) are pseudo-colored TRPL images excited at 640 nm at various fluences, specifically: (a) 0.071 μJ cm 2 , (b) 0.177 μJ cm 2 , (c) 0.354 μJ cm 2 , (d) 0.707 μJ cm 2 , (e) 1.415 μJ cm 2 , and (f) 2.829 μJ cm 2 As the excitation fluence increases, the tail (white area) shows a significant weakening, indicating a shorter photoluminescence lifetime.

[0228] Figure 14B

[0229] Figure 14B It is the TRPL decay kinetics curve of the square root of photoluminescence intensity versus delay time at various excitation integrated fluxes and its global fitting.

[0230] Figure 15A

[0231] Figure 15A Figure 1 is a series of images showing the fluence-dependent TRPL of 3D / PEAI stacked films. (a) to (f) are pseudo-colored TRPL images excited at 640 nm at various fluences, specifically: (a) 0.071 μJ cm 2 , (b) 0.177 μJ cm 2 , (c) 0.354 μJ cm 2 , (d) 0.707 μJ cm 2, (e) 1.415 μJ cm 2 , and (f) 2.829 μJ cm 2 As the excitation fluence increases, the tail (white area) shows a significant weakening, indicating a shorter photoluminescence lifetime.

[0232] Figure 15B

[0233] Figure 15B It is the TRPL decay kinetics curve of the square root of photoluminescence intensity versus delay time at various excitation integrated fluxes and its global fitting.

[0234] Figure 16A

[0235] Figure 16A A series of images showing the fluence-dependent TRPL of 3D / PEA2ZnX4 stacked films. (a) to (f) are pseudo-colored TRPL images excited at 640 nm at various fluences, specifically: (a) 0.071 μJ cm 2 , (b) 0.177 μJ cm 2 , (c) 0.354 μJ cm 2 , (d) 0.707 μJ cm 2 , (e) 1.415 μJ cm 2 , and (f) 2.829 μJ cm 2 As the excitation fluence increases, the tail (white area) shows a significant weakening, indicating a shorter photoluminescence lifetime.

[0236] Figure 16A

[0237] Figure 16B It is the TRPL decay kinetics curve of the square root of photoluminescence intensity versus delay time at various excitation integrated fluxes and its global fitting.

[0238] Figure 17A

[0239] Figure 17A It shows -NH3 in PEA2FAPb2I7 passivator + Schematic illustration of the passivating interaction between the groups and the negatively charged A-site cation vacancy (VA) defect. For simplicity, only representative fragments taken from the single crystal structure of the PEA2FAPb2I7 passivator are shown here.

[0240] Figure 17B

[0241] Figure 17BSchematic diagram showing the passivating interaction between the -NH3+ group in the PEA2ZnX4 passivator and the negatively charged A-site cation vacancy (VA) defect. For simplicity, only representative fragments taken from the single crystal structure of the PEA2ZnX4 passivator are shown here.

[0242] Figure 17C

[0243] Figure 17C Schematic diagram showing the passivating interaction between halide anions and positively charged halide vacancies (Vx) defects in the PEA2FAPb2I7 octahedron [PbI6]. For simplicity, only representative fragments taken from the single crystal structure of the PEA2FAPb2I7 passivator are shown here.

[0244] Figure 17D

[0245] Figure 17D Schematic diagram showing the passivating interaction between the halide anions of the PEA2ZnX4 tetrahedron [ZnI4] and the positively charged halide vacancy (Vx) defect. For simplicity, only representative fragments taken from the single crystal structure of the PEA2ZnX4 passivator are shown here.

[0246] Figure 18A

[0247] Figure 18A It is -NH3 of PEA2FAPb2I7 + 2D ESP map of nitrogen atoms in the passivating group. All 2D planes are extracted based on the target atomic coordinates, and for simplicity, only representative fragments taken from the single crystal structure of the PEA2FAPb2I7 passivator are shown here.

[0248] Figure 18B

[0249] Figure 18B It is -NH3 of PEA2ZnX4 + 2D ESP map of nitrogen atoms in the passivating group. All 2D planes are extracted based on the target atomic coordinates, and for simplicity, only representative fragments taken from the single crystal structure of the PEA2ZnX4 passivator are shown here.

[0250] Figure 18C

[0251] Figure 18C This is the 2D ESP map of I atoms in the PEA2FAPb2I7 octahedron [PbI6].

[0252] Figure 18D

[0253] Figure 18D This is the 2D ESP diagram of the I atom in the PEA2ZnX4 tetrahedron [ZnI4].

[0254] Figure 19A

[0255] Figure 19A Schematic diagram of the quasi-2D PEA2FAPb2I7 passivator viewed from the (i) side and from the (001) plane.

[0256] Figure 19B

[0257] Figure 19B Schematic diagram of 0D PEA2ZnX4 passivator viewed from the (i) side and from the (001) plane.

[0258] Figure 20A

[0259] Figure 20A A series of Kelvin probe force microscopy (KPFM) images of perovskite films deposited on ITO-coated glass substrates ((i) control, (ii) PEAI, and (iii) PEA2ZnX4), where the color scale indicates the CPD intensity, ranging from 1.0 V to 2.8 V.

[0260] Figure 20B

[0261] Figure 20B corresponds to Figure 20A Figure 5. Distribution plots of the CPD statistical distribution of perovskite films deposited on ITO-coated glass substrates ((i) control, (ii) PEAI, and (iii) PEA2ZnX4).

[0262] Figure 20C

[0263] Figure 20C corresponds to Figure 20A UPS spectra of perovskite films deposited on ITO-coated glass substrates ((i) control, (ii) PEAI and (iii) PEA2ZnX4). f The small vertical lines on the left and right panels of the UPS spectrum indicate the secondary electron cutoff and the valence band edge, respectively.

[0264] Figure 21A

[0265] Figure 21A It is Rb5Cs 10 UV-visible spectra of 3D perovskite films.

[0266] Figure 21B

[0267] Figure 21B is the UV-visible spectrum of PEA2FAPb2I7 film.

[0268] Figure 21C

[0269] Figure 21C is the UV-visible spectrum of PEA2ZnICl3 film.

[0270] Figure 22A

[0271] Figure 22A Schematic diagram of charge transport at the nN heterojunction interface based on intrinsic thermal electron emission and quantum tunneling mechanisms.

[0272] Figure 22B

[0273] Figure 22B Schematic diagram of the distribution of the LD overlayer on a 3D perovskite surface. There are both thin and thick regions of the LD overlayer. The former can be thin enough to enable charge transport via tunneling, while carriers in the thick regions can also diffuse to adjacent thin regions for transport.

[0274] Figure 22C

[0275] Figure 22C It is a schematic diagram of the formation process of nN homotype heterojunction. vac Indicates vacuum degree, E 内建 represents the built-in electric field at the junction, in eV. The positive and negative signs represent the positively charged and negatively charged regions at the junction, respectively. The dotted arrows represent E 内建 The upper arrow indicates the direction of photoinduced electron transfer, and the lower arrow with a red cross indicates the direction of photoinduced hole blocking. The Δ symbol represents the Fermi level difference at the junction.

[0276] Figure 23

[0277] Figure 23 Figure 2 is a graph showing the relationship between the zero-saturation voltage and irradiance at room temperature for control, 3D / PEAI, and 3D / PEA2ZnX4 PSCs. The horizontal line indicates the saturation voltage level. V is estimated based on the saturation zero-saturation voltage. bi They are 1.13V, 1.19V and 1.23V respectively.

[0278] Figure 24

[0279] Figure 24 The energy level diagrams illustrate the possible field-effect passivation mechanisms in 3D perovskite surfaces, 3D / Pb-LD heterojunctions, and 3D / Zn-LD heterojunctions.

[0280] Figure 25

[0281] Figure 25 Energy level diagram illustrating the perovskite / C60 interface composite comparison between 3D perovskite surface, 3D / Pb-LD structure, and 3D / Zn-LD structure.

[0282] Figure 26

[0283] Figure 26 A is a cross-sectional SEM image of the disclosed 3D / LD PSC. The magnified image shows the LD layer thickness. The LD capping material is PEA2ZnX4, and the LD capping layer thickness is estimated to be approximately 20 nm. The scale bar represents 200 nm in the full image and 100 nm in the magnified image.

[0284] Figure 27

[0285] Figure 27 This is a 3D AFM image of a control 3D perovskite film, showing some valleys deeper than the estimated capping layer thickness (about 20 nm).

[0286] Figure 28

[0287] Figure 28 is the chemical structure of the TPPi molecule.

[0288] Figure 29A

[0289] Figure 29A A series of images showing the fluence-dependent TRPL of 3D perovskite films in the presence of TPPi passivation. (a) to (f) are pseudo-colored TRPL images excited at 640 nm at various fluences, specifically, (a) 0.071 μJ cm 2 ,(b)0.177μJcm 2 ,(c)0.354μJcm 2 ,(d)0.707μJcm 2 ,(e)1.415μJcm 2 , and (f) 2.829 μJ cm 2 .

[0290] Figure 29B

[0291] Figure 29B It is the TRPL decay kinetics curve of the square root of photoluminescence intensity versus delay time at various excitation integrated fluxes and its global fitting.

[0292] Figure 30A

[0293] Figure 30A Figure 2. Current density versus voltage (J–V curve) of the champion 3D / PEA2ZnX4 PSC in other TPPi passivation conditions. FS represents the forward scan, and RS represents the reverse scan.

[0294] Figure 30B

[0295] Figure 30B Figure 2 is a plot of the stable power output (SPO) versus time for the target 3D / PEA2ZnX4 PSC with additional TPPi passivation, measured at a 1.02 V bias.

[0296] Figure 30C

[0297] Figure 30C It is a histogram of the PCE distribution of 103 independent target PSCs, where the curve represents the probability density function of the normal distribution.

[0298] Figure 30D

[0299] Figure 30D is the external quantum efficiency (EQE) spectrum of the target PSC.

[0300] Figure 31A

[0301] Figure 31A Figure 2 shows the normalized PCE curve over time, representing the operational stability of control and target PSCs under N2 conditions at the MPP under white light-emitting diode (LED) illumination with an effective irradiance equivalent to one solar day. The initial PCEs of the control and target PSCs were (18.6±0.1)% and (21.7±0.1)%, respectively. The device temperature was approximately 40°C during testing. Error bars represent the standard deviation of three separate measurements, and the center of the error bars represents the mean.

[0302] Figure 31B

[0303] Figure 31B This is the relationship between current density and voltage (J–V curve) of the target PSC before and after MPP tracking for 1009 hours.

[0304] Figure 32A

[0305] Figure 32A (i) AFM image and (ii) graph showing the morphology of a control 3D perovskite film in air (relative humidity approximately 64%) without encapsulation before aging under 1 sun illumination for 13 h. Scale bar represents 20 μm.

[0306] Figure 32B

[0307] Figure 32B (i) AFM image and (ii) graph showing the morphology of a control 3D perovskite film after aging for 13 h in air (relative humidity approximately 64%) under 1 sun illumination without encapsulation, demonstrating the morphological changes. Scale bar represents 20 μm.

[0308] Figure 33A

[0309] Figure 33A (i) AFM image and (ii) graph showing the morphology of the target 3D / LD stack film before aging for 13 h under 1×sun illumination in air (relative humidity approximately 64%) without encapsulation. Scale bar represents 20 μm.

[0310] Figure 33B

[0311] Figure 33B (i) AFM image and (ii) graph showing the morphology of the target 3D / LD stack film after aging for 13 h in air (relative humidity approximately 64%) under 1x sun illumination without encapsulation, showing the morphological changes. Scale bar represents 20 μm.

[0312] Figure 34

[0313] Figure 34 Schematic diagram demonstrating the improved stability of the 3D / LD structure.

[0314] Figure 35A

[0315] Figure 35A is an image of the steady-state contact angle of deionized water on top of the glass / PEA2ZnI4 film.

[0316] Figure 35B

[0317] Figure 35B is an image of the steady-state contact angle of deionized water on top of the glass / PEAI film.

[0318] Figure 35C

[0319] Figure 35C is an image of the steady-state contact angle of deionized water on top of the glass / ZnI2 film.

[0320] Figure 36

[0321] Figure 36A series of photoluminescence (PL) images, consisting of: PL images of a control 3D perovskite film before (a) and after (b) aging under 1×sun illumination in air (relative humidity approximately 64%) without encapsulation for 13 hours; PL images of the target 3D / LD stack film before (c) and after (d) aging under the same conditions; and magnified PL images of the areas shown in (c) (e) and (d) (f). The sample was excited by a 473 nm continuous wave laser. Scale bar represents 100 μm.

[0322] Figure 37

[0323] Figure 37 Figure 2 is a plot of normalized PCE versus time, testing the thermal stability of control and target 3D / LD PSCs at 85°C and approximately 50% relative humidity. Error bars represent the standard deviation of three independent devices, and the center of the error bars represents the mean.

[0324] Figure 38

[0325] Figure 38 It is the original BA2ZnI2Cl2 and Cs 15 A series of XRD patterns of / BA2ZnI2Cl2 stacked films.

[0326] Figure 39

[0327] Figure 39 is the original PEA2CoI2Cl2 and Cs 15 A series of XRD patterns of PEA2CoI2Cl2 stacked films. The slight shift of the low-angle characteristic XRD peak position of PEA2CoI2Cl2 is due to the interaction of I- with Cs in PEA2CoI2Cl2. 15 This is caused by halogen exchange between Cl- in the perovskite, which is similar to PEA2ZnX4. Example

[0328] Non-limiting embodiments of the present disclosure will be described in further detail by referring to specific examples, but the specific examples should not be construed as limiting the scope of the present disclosure in any way.

[0329] Example 1: Preparation of Half Precursor (HP) and Full Precursor (FP) Covering Solutions

[0330] Conventional HP covering solution was prepared by dissolving PEAI (available from Greatcell Energy Ltd, Australia) in isopropyl alcohol (IPA) (available from Sigma-Aldrich, St. Louis, MO, USA).

[0331] The FP covering solution of the present disclosure was prepared as follows:

[0332] The PEA2PbI4 FP covering solution was prepared by dissolving 31.3 mg of PbI2 (purchased from TCI, Chuo-ku, Tokyo, Japan) and 33.9 mg of phenylethylammonium iodide (PEAI) (purchased from Greatcell Energy Ltd, Australia) in 4 mL of acetonitrile (ACN) (17 mM) (purchased from Sigma-Aldrich, St. Louis, MO, USA). Other FP covering solutions, including BA2PbI4, PMA2PbI4, (NMA)2PbI4, BA2ZnX4 (X = Cl / I), PEA2ZnX4 (X = Cl / I), and PEA2CoX4 (X = Cl / I) (BA = n-butylammonium; PMA = benzylammonium; NMA = 1-naphthylmethylammonium), were prepared in the same manner as the PEA2PbI4 FP covering solution at the same concentration of 17 mM. The (NMA)2PbI4 precursor was specifically dissolved in 1 mL of ACN mixed solvent containing 50 μL of methylamine (Sigma-Aldrich, St. Louis, MO, USA). The PEA2PbI4-PEA2ZnX4 mixed FP covering solution was prepared by dissolving 62.7 mg of PbI2, 18.5 mg of ZnCl2 (Sigma-Aldrich, St. Louis, MO, USA), and 135.5 mg of PEAI in 8 mL of ACN.

[0333] Example 2: Device preparation and characterization

[0334] Device fabrication

[0335] Use water-based cleaners ( Patterned ITO-coated glass substrates (purchased from Shenzhen Huayu Union Technology Co., Ltd., China) were ultrasonically cleaned for approximately 20 minutes using a 5% ion ion cleaning agent (purchasing agent, purchased from Sigma-Aldrich, St. Louis, MO, USA), deionized water, acetone, and ethanol. These substrates were then treated with UV-ozone for 15 minutes before use. All spin coating processes were performed in an N2-filled glove box (O2 <10 ppm, H2O <1.0 ppm).

[0336] A polytriarylamine (PTAA) solution (2 mg mL in toluene) (purchased from Xi'an Polymer Light Technology Corp., Xi'an, Shaanxi, China) was stirred at 2000 rpm. -1 ) was spin-coated on a clean ITO substrate for 60 seconds to deposit a hole-transporting PTAA layer, followed by annealing at 100°C for 10 min.

[0337] Rb0.05 Cs 0.10 FA 0.85 PbI 2.8 Cl 0.2 (Rb5Cs 10 The perovskite precursor contained 414.9 mg PbI2, 27.8 mg PbCl2 (purchased from Sigma-Aldrich, St. Louis, MO, USA), 146.2 mg formamidine hydroiodide (FAI) (purchased from Greatcell Energy Ltd, Australia), 26.0 mg CsI (purchased from Sigma-Aldrich, St. Louis, MO, USA), and 10.6 mg RbI (purchased from Sigma-Aldrich, St. Louis, MO, USA) in 1 mL of anhydrous DMF:DMSO (4:1, v / v) (both solvents were purchased from Sigma-Aldrich, St. Louis, MO, USA). Cs 0.15 FA 0.85 PbI 2.8 Cl 0.2 (Cs 15 ) The perovskite precursor contains 414.9 mg PbI2, 27.8 mg PbCl2, 146.2 mg FAI, and 39.0 mg CsI in 1 mL of anhydrous DMF:DMSO (4:1, v / v). 0.05 (MA 0.15 FA 0.85 ) 0.95 PbI 2.55 Br 0.45 The (CsMAFA) perovskite precursor contained 780.3 mg PbI2, 112.9 mg PbBr2, 277.8 mg FAI, 26.0 mg CsI, and 31.9 mg MABr (purchased from Greatcell Energy Ltd, Australia) in 2 mL anhydrous DMF:DMSO (4:1, v / v). The corresponding precursor solution was spin-coated on an ITO / PTAA substrate at 1000 rpm for 10 seconds (5-second ramp) and at 4000 rpm for 45 seconds (1-second ramp) to deposit Rb5Cs 10 、Cs 15 The perovskite film was prepared by adding 150 μL of 1,2-dichlorobenzene (DCB) (purchased from Sigma-Aldrich, St. Louis, MO, USA) to the substrate 10 seconds before the end of the process to induce rapid crystallization of the perovskite. The prepared perovskite film was then annealed at 110°C for 10 min.

[0338] Next, the HP or FP covering solution was spin-coated onto the perovskite film at a speed of 5000 rpm (1500 rpm was used for XRD and GIWAXS / GISAXS samples to obtain better signals) for 30 seconds. After the substrate began to rotate, the FP covering solution was quickly injected onto the 3D perovskite surface to minimize possible corrosion of the underlying 3D perovskite. The film was then annealed at 100°C for 10 minutes.

[0339] As needed, tris(2,4-tert-butylphenyl) phosphate (TPPi) toluene solution (6 mg mL) was spin-coated at 5000 rpm. -1 ) (TPPi and toluene were purchased from Sigma-Aldrich, St. Louis, MO, USA) for 30 seconds to prepare an additional TPPi passivation layer. Finally, the device was passed through a metal shadow mask (6.0 mm active area for small area devices). 2 Or for large area devices the effective area is 1.218 cm 2 ) 50nm C on the membrane 60 (purchased from Puyang Yongxin Fullerene Technology Co., Ltd., Puyang, China), 6 nm bathocuproin (BCP) (purchased from Xi'an PolymerLight Technology Corp., Xi'an, Shaanxi, China) and 100 nm Ag were sequentially thermally evaporated (under a temperature of less than 5.0 × 10 -4 To minimize unexplained reflections and possible edge effects, a 100 nm LiF (Sigma-Aldrich, St. Louis, MO, USA) layer was evaporated onto the glass side of the ITO substrate as an antireflection layer, and a non-reflective black metal aperture mask (4.0 mm aperture for small area devices) was adhered to the glass side of the ITO substrate as needed. 2 Or about 0.973 cm for large area devices. 2 ). In the PSC, the Ag electrode was replaced by a Cr (5 nm) / Au (100 nm) electrode for stability testing.

[0340] Device characterization

[0341] The current density-voltage (JV) curves of the PSCs were recorded using a Keithley 2400 source meter (Keithley Instruments, Cleveland, Ohio, USA) under AM 1.5G solar illumination conditions simulated by a ScienceTech UHE-NSC AAA solar simulator (Sciencetech, Ontario, Canada). For the disclosed PSCs, the effective irradiance of the solar simulator was adjusted to one sun intensity (100 mW cm) by using an Oriel PV Reference Cell System (91150 V) (Newport, Irvine, California, USA) and correcting for possible spectral mismatches. -2 ). In the forward or reverse scan direction from -0.2V to 1.25V / 1.20V or 1.25V / 1.20V to -0.2V, the -1 The JV curves were measured at a scan rate of 100 nm. Unless otherwise stated, the JV curves presented were obtained in a N2-filled glove box (O2 <10 ppm, H2O <1.0 ppm) at room temperature in the reverse scanning direction. The JV curves were initially measured without an aperture mask. The JV curves were then calculated by subtracting the JV curves between the measurements with and without an aperture mask in the specific photovoltaic system. SC Difference, for the values ​​obtained with the aperture mask, for the measured J SC Calibration is performed, although J SC The difference is as small as 0.37 mA cm caused by unexplained reflections and possible edge effects. -2 (See Table 1). By measuring the results with an aperture mask, or based on the calibrated J SC Spectral response and external quantum efficiency analysis were performed on a Zolix Solar Cell Scan100 measurement system (Zolix Instruments Co., Ltd., Beijing, China) and a QEPVSI-b setup (Newport, Irvine, CA, USA).

[0342] Table 1. Comparison of photovoltaic parameters of target 3D / PEA2ZnX4 PSCs with additional passivation measured with and without aperture mask. a Here, 3D perovskite and PEA2ZnX4 are Rb5Cs 10 and PEAZnI2Cl2.

[0343]

[0344] aData include mean and standard deviation calculated from 22 individual devices. b ΔJSC is the J between the measurements with and without the aperture mask SC difference.

[0345] Example 3: Stability test

[0346] Run stability test

[0347] The operational stability test of the disclosed PSC was conducted in a N2-filled glove box (O2<10ppm, H2O<1.0ppm) at the maximum power point (MPP) under the illumination condition of a white light LED lamp with an effective irradiance equivalent to one solar intensity. An example of the detailed tracking process is as follows, and the relevant data are shown in Table 2: (1) As described above, the initial PCE of the PSC was measured under a simulated AM 1.5G AAA solar simulator with an effective irradiance of one solar intensity. The obtained initial PCE and J SC Marked as PCE (0h,SS) and J SC(0h,SS) (SS stands for solar simulator). (2) Then, the PSC is tested under the irradiation of white light LED lamp. SC (marked as J SC(0h,LED) ) is adjusted to be close to J in step (1) SC(0h,SS) The effective irradiance of the white LED lamp on the specific PSC was determined to be one solar light intensity. Then a certain voltage bias was selected and applied to the PSC to generate the MPP output using a Keithley 2602B source meter (Keithley Instruments, Cleveland, Ohio, USA). The PSC was operated continuously under the MPP condition for about 22 hours. (3) After the first 22 hours of MPP operation, J was measured again under the white LED lamp. SC and marked as J SC(22h,LED) The J of the same device was also measured under solar simulator irradiation. SC and marked as J SC(22h,SS) .J SC(22h,LED) With J SC(22h,SS) The possible difference between the two measurements may be caused by the change in irradiance of the white LED lamp after 22 hours of operation, rather than the change in device performance between the two measurements, because J SC(22h,LED) and J SC(22h,SS) are measured simultaneously. SC(22h,LED) With J SC(22h,SS) The negligible difference between the two indicates that the irradiance of the white LED lamp is relatively stable. (4) A longer operation test was also conducted by repeating steps (2) and (3). The operational stability results presented are based on PCE data measured under solar simulator irradiation.

[0348] Table 2. Comparison of representative photovoltaic parameters of the target PSC before and after the first 22 h of MPP operation.

[0349]

[0350] a J SC(SS) represents the J measured under solar simulator conditions SC . b J SC(LED) Indicates J measured under white light LED conditions SC . c PCE (SS) represents the PCE measured under solar simulator conditions. d ΔJ SC Indicates J SC(LED) With J SC(SS) The data include the mean and standard deviation calculated from three measurements.

[0351] Thermal stability test

[0352] Thermal stability tests at 85°C were performed under ambient conditions (relative humidity of approximately 50%) or in an N2-filled glove box (O2 <10ppm, H2O <1.0ppm). Before starting the test in air, the devices were simply encapsulated with a substrate, while the devices tested in N2 were not encapsulated. Simple substrate encapsulation was achieved by storing the original device directly in a small commercial sealed box, which was then placed in an 85°C oven for testing. It should be noted that simple substrate encapsulation cannot strictly isolate the air. In the relevant devices, the widely used tricationic CsMAFA 3D perovskite was used for testing.

[0353] Example 4: Fabrication and Characterization of 3D / LD Stacked Films

[0354] The comparison between the proposed FP process and the conventional HP process is shown in Figure 1A As shown. Antisolvents such as IPA are usually used to prepare HP solutions, while acetonitrile (ACN), a slightly more polar solvent, is used to dissolve FP components, especially metal halides, as described in Example 1. For simplicity, a solvent with Figure 1B The structures of PEA2PbI4 and PEA2ZnX4 (X = Cl / I) are shown and are further discussed as representatives of FP-based LD capping materials. On the other hand, the ubiquitous PEAI is selected as a representative of the HP capping method. It is worth noting that the characteristic low-angle XRD peaks ( Figure 1C and Figure 1D ) provides strong direct evidence for the existence of the corresponding LD material in the 3D / LD film.0.05 Cs 0.10 FA 0.85 PbI 2.8 Cl 0.2 (abbreviated as Rb5Cs 10 )( Figure 1E and Figure 1F ) or Cs 0.15 FA 0.85 PbI 2.8 Cl 0.2 (abbreviated as Cs 15 )( Figure 1G and Figure 1H ) of the bottom 3D perovskite and completely converted into quasi-2D PEA2FAPb2I7. However, for the conventional capping method, although most of the PEAI salts are converted into PEA2FAPb2I7 under the same post-treatment conditions, some PEAI salts still remain on the two 3D perovskites ( Figure 1E and Figure 1G The excellent controllability of the FP technique for LD capping layer growth in this disclosure is further demonstrated by the successful realization of a 2D (NMA)2PbI4 capping layer with excellent intrinsic stability on a 3D perovskite ( Figure 2 ), while the traditional HP process cannot achieve this due to the difficulty in the reaction between NMAI salt and 3D perovskite. Interestingly, it was found that in Rb5Cs 10 Both PEA2ZnX4 and PEA2FAPb2I7 phases were detected in the PEA2ZnX4 / PEA2ZnX4 film ( Figure 1E ), but in Cs 15 / PEA2ZnX4 film only contains PEA2ZnX4( Figure 1G ). It is also noted that I in PEA2ZnX4 - With Rb5Cs 10 or Cs 15 Cl in perovskite - Halogen exchange always occurs between them, eventually leading to PEA2ZnI 4-x Cl x (x≥2) Cl enrichment composition ( Figure 1E and Figure 1G ), where the estimated x values ​​are shown in Table 3. Hereinafter, unless otherwise specified, the Zn-based covering components are represented by the simplified formula PEA2ZnX4, where X is Cl - , I - or a mixture thereof.

[0355] Table 3. Characteristic XRD peak positions of PEA2ZnX4 (see Figure 1C 、 1E and 1G) estimated PEA2ZnI in 3D / PEA2ZnX4 (X=Cl / I) stacked films4-x Cl x Covering the x value of the product

[0356] aThe value of x here is estimated to be around 3 because the characteristic XRD peak position is located between those of PEA2ZnI2Cl2 and PEA2ZnCl4.

[0357] In order to reveal the relationship between PEA2ZnX4 and Rb5Cs 10 Possible reaction pathways between perovskites. RbCl / PEA2ZnX4 stacked films were studied under similar conditions and found that Rb + With PEA + Partial exchange to generate PEAX salt ( Figure 3 ). Exchanged Rb + It is likely to be incorporated into the PEA2ZnX4 structure to form (PEA 1-y Rb y )2ZnX4, which is a reasonable inference because the full width at half maximum (FWHM) value of the characteristic diffraction peak of PEA2ZnX4 is almost doubled ( Figure 3 ), and considering that Rb2ZnX4 has the same β-K2SO4 type crystal structure as PEA2ZnX4. Therefore, it is concluded that the covered PEA2ZnX4 is similar to Rb5Cs 10 Perovskite partially reacts via Rb + With PEA + Cation exchange between the production (PEA 1-y Rb y )2ZnX4 and PEA2FAPb2I7. The possible reactions between the disclosed LD capping materials and 3D perovskites are summarized in Table 4.

[0358] Table 4. Comparison of possible reactions between capping materials and 3D perovskites and the corresponding products / residues.

[0359]

[0360] a A=Rb,Cs,FA;X=Cl / I.

[0361] By rough quantitative XRD analysis ( Figure 4A –4C and Table 5), further confirmed that Rb5Cs 10 The possible conversion of PEA2ZnX4 in the / PEA2ZnX4 stacked films was estimated by using the integrated intensity of the corresponding characteristic diffraction peaks. 10 / PEA2ZnX4 and Rb5Cs 10 / PEA2PbI4 stacked films under the same preparation and measurement conditions, as well as similar chemical environments, it is reasonable to assume that the crystallinity and texture of PEA2FAPb2I7 in these two stacked films are roughly the same, which indicates that Rb5Cs 10 PEA2FAPb2I7 and Rb5Cs in PEA2ZnX4 10 The ratio of PEA2FAPb2I7 in PEA2PbI4 / PEA2FAPb2I7 can be estimated by directly comparing the integrated intensities of the PEA2FAPb2I7 diffraction peaks. It is also inferred that if PEA2ZnX4 is completely converted to PEA2FAPb2I7, then Rb5Cs 10 The diffraction peak intensity of PEA2FAPb2I7 of / PEA2ZnX4 should be close to that of Rb5Cs 10 / PEA2PbI4 PEA2FAPb2I7 diffraction peak intensity. This is because in Rb5Cs 10 In the PEA2PbI4 / PEA2PbI4, PEA2PbI4 has been completely converted into PEA2FAPb2I7, and due to the same manufacturing conditions, the PEA + Therefore, by simply comparing Rb5Cs 10 / PEA2ZnX4 and Rb5Cs 10 / PEA2PbI4 PEA2FAPb2I7 diffraction peak intensity, obtained Rb5Cs 10 The conversion rate of PEA2ZnX4 in Rb5Cs / PEA2ZnX4 was about 10% (Table 5), which indicated that 10 About 90% of PEA2ZnX4 in / PEA2ZnX4 was retained.

[0362] In order to test the reliability of the results, a similar analysis was performed to compare the Rb5Cs 10 / PEA2ZnX4 and Cs 15 / PEA2ZnX4 diffraction peak intensity, direct calculation of Rb5Cs 10 The retention rate of PEA2ZnX4 in / PEA2ZnX4 was similar, about 90% (Table 5). 10 Layer of Rb5Cs 10 / PEAI and Rb5Cs 10 The UV-Vis absorption spectrum of the PEA2PbI4 / PEA2PbI4 film shows a clear and strong exciton absorption peak at about 570 nm, which corresponds to PEA2FAPb2I7, while for Rb5Cs 10 / PEA2ZnX4 film, this peak is hardly observed ( Figure 5A –5C). Therefore, it can be inferred that PEA2FAPb2I710 / PEA2ZnX4 films is a minor covering byproduct, although it is difficult to be observed in Rb5Cs due to the intrinsic weak absorption of PEA2ZnX4. 10 PEA2ZnX4( Figure 5C ). This is consistent with the quantitative XRD analysis results above. In short, the covered PEA2ZnX4 is mainly retained in the Rb5Cs 10 On perovskite, with Rb5Cs 10 The perovskite reacts only slightly, producing a small amount of PEA2FAPb2I7 byproduct.

[0363] Table 5. Estimated proportions of the components in the covered product based on quantitative XRD analysis (see Figure 4).

[0364]

[0365] a By comparing Rb5Cs 10 / PEA2ZnI4 and Rb5Cs 10 The ratio was estimated by comparing the peak area of ​​PEA2FAPb2I7 in PEA2PbI4. 10 / PEA2ZnI4 and Cs 15 / PEA2ZnX4 in PEA2ZnI4 to estimate the ratio.

[0366] Grazing-incidence wide-angle / small-angle X-ray scattering (GIWAXS / GISAXS) was used to further evaluate the orientation of the LD capping material relative to the substrate ( Figure 6A –6H). Grazing incidence X-ray scattering (GIXS) is widely used to analyze the crystal orientation / lattice spacing / crystal correlation length, domain size / domain shape, and phase separation / phase purity of functional materials in photovoltaic devices. Figure 6A The reflection geometry of GIXS is shown. The X-ray beam is incident at a very shallow angle α. i (usually α i <1°) hits the sample surface and f The X-ray beam is scattered at an out-of-plane angle Ψ. Typically, the x-axis is along the X-ray beam direction, the y-axis is parallel to the sample surface, and the z-axis is along the surface normal, with the scattering plane being the (x,z) plane. The scattered signal from the sample is then recorded on a 2D X-ray detector. By varying the distance between the sample and the detector, GIWAXS / GISAXS signals can be obtained.

[0367] Based on the Nano-inXider of the Xenocs system, Ψ rotation enables the sample to be rotated around the beam and different configurations (in-plane / out-of-plane GIWAXS / GISAXS) can be achieved (see Figure 6B When Ψ = 90°, the recorded patterns correspond to in-plane GIWAXS and GISAXS, with overlap in the q scattering vector. When Ψ = 0°, out-of-plane GIWAXS is achieved. When Ψ = 180°, out-of-plane GIWAXS is measured.

[0368] The incident monochromatic X-ray beam has a wave vector k i And wave number k0=2π / λ (λ is the wavelength of X-ray, its value is inherent in the metal anode), along k f The scattered wave vector q and its three related components (q x ,q y and q z ) is defined by the following equation:

[0369] q=(q x ,q y ,q z )=k f –k i (E1)

[0370]

[0371]

[0372]

[0373] When the lateral structure is missing, due to pure specular scattering, it satisfies α i =α f Diffuse scattering arises from a lateral shift in the refractive index, which results in α i ≠α f .

[0374] The control 3D film shows Debye–Scherrer-like rings, while the 3D / LD stacked films exhibit additional Bragg spots, whose positions correspond to the positions of the relevant peaks in their XRD patterns. Interestingly, all the Bragg spots shown in the disclosed 3D / LD stacked films are along the Q z This indicates that the LD capping material is preferentially oriented with its (0k0) plane parallel to the substrate, i.e., the b-axis is oriented perpendicular to the substrate. This is consistent with the orientation of most reported LD capping materials prepared by conventional HP methods.

[0375] High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and energy-dispersive X-ray spectroscopy (EDX) were used to Figure 7A –7D), and time-of-flight secondary ion mass spectrometry (ToF-SIMS), further confirmed the presence and distribution of the Zn-based capping layer on the 3D perovskite surface ( Figure 8A and 8B ).exist Figure 7C In the Zn-LD layer, no lattice fringes were observed, which may be due to the relatively low crystallinity of 0DPEA2ZnX4 and / or the damage caused by FIB during the sample thin film preparation. Figure 8B In the 3D / PEA2ZnX4 device, the Zn signal is only observed between the C and Pb signals, while it is absent in the control device, indicating that the PEA2ZnX4 capping material is mainly distributed in the C 60 At the interface between the Zn and Pb layers and the 3D perovskite. It is important to note that the appearance of the Zn and Pb signals occurs almost simultaneously at the moment of sputtering. This is because on the relatively rough 3D perovskite surface, the PEA2ZnX4 capping layer with a smaller optimal thickness may be discontinuous rather than conformal, and therefore cannot fully cover the 3D perovskite surface.

[0376] In addition, the Zn-based capping material may form a thin film on the surface of the 3D perovskite, which is inferred from its distribution morphology on the ITO substrate ( Figure 9A –9C). Figure 9A –9C, it is worth noting that it is quite difficult to directly determine the PEA2ZnX4 capping layer on the 3D perovskite surface through the possible different morphologies between the two due to the relatively thin PEA2ZnX4 capping layer and the relatively rough 3D perovskite surface, which makes the PEA2ZnX4 capping layer almost “invisible” under SEM, and therefore, the 3D perovskite morphology is observed everywhere.

[0377] ITO / PEA2ZnX4 films were also studied to estimate the possible coverage of PEA2ZnX4 in 3D / PEA2ZnX4 films. It is worth noting that most areas of the 3D perovskite surface are likely to be fully covered by the PEA2ZnX4 capping layer, but there are still a few areas with incomplete coverage. Lattice microstrain analysis (Table 6) shows that although the Zn-based capping layer has a different crystal structure from the underlying 3D perovskite, the Zn-based capping layer hardly induces any additional lattice strain on the underlying 3D perovskite. It is also worth noting that the FP-based capping solution hardly changes the cross-sectional morphology of the underlying 3D perovskite ( Figure 10 ), indicating negligible damage to the underlying 3D perovskite. In addition, it was found that all capping layers effectively reduced the roughness of the 3D perovskite film ( Figure 11A –11E), which may be attributed to the capping material filling the valley region on the 3D perovskite surface.

[0378] Table 6. Lattice microstrain analysis of 3D and 3D / PEA2ZnI4 stacked films. The 3D perovskite here is Cs 15 .

[0379]

[0380] a β hkl is the full width at half maximum of the peak, which is related to the lattice microstrain, domain size and instrument contribution. Considering that the control 3D sample and the 3D / PEA2ZnI4 sample were made using the same instrument and have similar domain sizes, the β hkl The difference in β can be mainly attributed to the different lattice microstrain, which is reasonable. hkl / 4tanθ, estimate the lattice microstrain.

[0381] Example 5: Comparison of Photovoltaic Performance of 3D / LD PSCs

[0382] Then, ITO / PTAA / 3D / LD / C 60 / BCP / Ag General Configuration ( Figure 12A ), p–i–n structured 3D / LDPSCs were studied. Unless otherwise stated, all 3D perovskites are Rb5Cs 10 . Figures 12B to 12E Table 7 compares the open circuit voltage (VOC), short circuit current density (J SC ), fill factor (FF), and power conversion efficiency (PCE) values, where the various capping materials were fabricated using either the conventional HP process or the disclosed FP process. The capping layers were prepared using their respective optimized conditions to ensure a fair comparison (Table 8). Compared to the control device with an average PCE of 19.3 ± 0.3%, both the conventional HP-based 3D / PEAI devices and the FP-based 3D / PEA2PbI4 devices showed improved performance of 20.5 ± 0.8% and 20.8 ± 0.5%, respectively, while the 3D / PEA2ZnX4 devices showed even greater improvements, with a remarkable PCE of 22.2 ± 0.3%. These improvements are primarily attributed to the V OC Enhanced. The performance of FP-based 3D / PEA2PbI4 devices is comparable to that of HP-based 3D / PEAI devices, which is attributed to the similar final capping composition (PEA2FAPb2I7). The better reproducibility (narrower PCE distribution) of FP-based 3D / PEA2PbI4 devices may be attributed to the excellent synthetic control of the LD capping layer by the FP technique. These results verify the feasibility and superiority of our FP technique for high-efficiency 3D / LD PSCs. The excellent performance of 3D / PEA2ZnX4 devices supports the potential advantage of PEA2ZnX4 as a LD capping material in 3D / LD PSCs, which is particularly advantageous in relatively large areas (approximately 1 cm 2) is also applicable to devices with high performance (Table 9). It is worth noting that the key covering component of high performance 3D / PEA2ZnX4 devices should be the intrinsic PEA2ZnX4 rather than the PEA2FAPb2I7 byproduct, because as demonstrated above, the PEA2ZnX4 residue is the main covering component (about 90%) in the 3D / PEA2ZnX4 stacked film. Considering that PEA2ZnX4 may be completely retained in the Cs 15 In order to eliminate the influence of a small amount of PEA2FAPb2I7 by-products on perovskite, a Cs-based 15 Thus, similar performance improvements were demonstrated (Table 10), which further confirms the intrinsic superiority of PEA2ZnX4 as LD capping materials in 3D / LD PSCs.

[0383] Table 7. Photovoltaic parameter statistics of PSCs without or with different capping materials. Here, 3D perovskites and PEA2ZnX4 are Rb5Cs 10 and PEAZnI2Cl2.

[0384]

[0385] aData include the mean and standard deviation calculated from 25 independent devices.

[0386] Table 8. Photovoltaic parameter statistics of PSCs based on various concentrations of capping materials. Here, 3D perovskite and PEA2ZnX4 are Rb5Cs 10 and PEAZnI2Cl2.

[0387]

[0388] aData include the mean and standard deviation calculated from 8 independent devices.

[0389] Table 9. The orifice area is relatively large (0.973 cm 2 )Photovoltaic parameter statistics of 3D / PEAI and 3D / PEA2ZnX4 PSCs.

[0390]

[0391] aData include the mean and standard deviation calculated from 10 independent devices.

[0392] Table 10. Photovoltaic parameter statistics of PSCs without or with different capping materials. Here, 3D perovskites and PEA2ZnX4 are Rb5Cs 10 and PEAZnI2Cl2.

[0393]

[0394] aData include the mean and standard deviation calculated from 13 independent devices.

[0395] Example 6: Evolution of Photoelectric Performance of 3D / LD PSCs

[0396] To elucidate the fundamental reason for the unusually enhanced device performance of the PEA2ZnX4 capping material, time-resolved photoluminescence (TRPL) analysis was performed to characterize the non-radiative recombination losses of carriers in the perovskite film.

[0397] Given that the final covering compositions and performances of HP-based 3D / PEAI and FP-based 3D / PEA2PbI4 devices are similar, the 3D / PEAI stacked films are considered as representatives of their Pb-based counterparts for comparison. Figure 13A As shown, at 0.177 μJ cm -2 At the same excitation integrated flux and 640 nm, the 3D / PEAI and 3D / PEA2ZnX4 stacked films both exhibited “long tails” in their pseudo-color TRPL maps relative to the control film, indicating a longer PL lifetime. Figure 13B A clearer comparison of the TRPL decay kinetics is shown. Flux-dependent TRPL analysis and corresponding global fits were also performed to extract the specific rate constant (k1) and lifetime (τ) of trap-mediated non-radiative recombination (i.e., Shockley–Read–Hall (SRH) recombination). The TRPL delay kinetics is associated with carrier recombination channels that depend on the excitation pulse fluence (initial carrier density). At very low excitation fluences, the trap-mediated non-radiative unimolecular recombination (first-order) channel dominates, resulting in a monoexponential dependence of the TRPL decay kinetics. As the excitation fluence increases, higher-order recombination channels, such as bimolecular electron-hole radiative recombination (second-order) and trimolecular Auger recombination (third-order), begin to contribute, leading to accelerated TRPL decay kinetics, which are generally governed by the following rate equation:

[0398]

[0399] Where N is the photoexcited carrier density, k1, k2, and k3 are the rate constants of the first-order, second-order, and third-order recombination, respectively.

[0400] To extract the specific recombination rate constant, the 5-μm ionomer was excited by a 640 nm femtosecond laser pulse at various fluences (0.071, 0.177, 0.354, 0.707, 1.415, and 2.829 μJ cm -2), a fluence-dependent TRPL analysis of the disclosed perovskite film was performed. The excitation fluence used was relatively low, and third-order Auger recombination was negligible under these conditions. Therefore, the k1 and k2 values ​​could be extracted by globally fitting the TRPL delay dynamics at various excitation fluences using a simplified rate equation (E6).

[0401]

[0402] The lifetime of the first-order trap-mediated recombination can then be calculated (τ=1 / k1).

[0403] It is observed that the k1 of 3D / PEA2ZnX4 is more significantly reduced than that of conventional 3D / PEAI, while τ is more significantly increased (Table 11), which indicates that PEA2ZnX4 is superior to traditional Pb-based counterparts in surface passivation to inhibit charge recombination. It is known that the chemical passivation effect of halometallate capping materials mainly comes from their interaction with A-site cation vacancies (V A ) and halogen vacancies (V X ) defects, which are considered to be the dominant defect type on the surface of 3D perovskites. Similarly, in the present disclosure, the main surface covering components PEA2FAPb2I7 in conventional 3D / PEAI films and PEA2ZnX4 in 3D / PEA2ZnX4 films can interact with V A and V X defect interactions, which depends on the presence of cationic amino groups (i.e. -NH3 + ) and halide anions ( Figures 17A-17D Although the PEA2FAPb2I7 and PEA2ZnX4 passivators have the same passivating groups, their interactions with defects may be different due to different chemical environments and structures, resulting in inconsistent passivation effects.

[0404] Table 11. Constants extracted from the global fit of the fluence-dependent TRPL decay dynamics of 3D perovskite films with no or different capping materials (see Figures 14–16).

[0405]

[0406] Density functional theory (DFT) calculations were also performed to evaluate the electronic structures of PEA2FAPb2I7 and PEA2ZnI4. Using the Vienna Atomic Simulation Package (VASP), electrostatic potential (ESP) maps of PEA2FAPb2I7 and PEA2ZnI4 based on their single crystal structures were calculated. The all-electron projector-augmented wave (PAW) method was used, and the PW86R exchange and PBE correlation potentials were implemented in the VASP code. The half-core (5d orbital) of the Pb atom was regarded as the valence electron, that is, Pb (5d10 6s 2 6p 2 ) atoms. The cutoff energy for the plane wave expansion of the wave function is 500 eV. Table 12 lists the lattice constants of PEA2FAPb2I7 and PEA2ZnI4. All atoms in the unit cell are fully optimized. The Hellman-Feynman force is less than For the DFT calculations, a 4×4×1 Monkhorst-Pack k-point grid was used for the Brillouin zone integration of PEA2FAPb2I7 and a 4×1×3 Monkhorst-Pack k-point grid was used for the Brillouin zone integration of PEA2FAPb2I7 and PEA2ZnI4, respectively. The vdW-DF2 method was used to calculate the van der Waals (VDW) interactions. The associated ESP plots were generated using the Visualization for Electronic and Structural Analysis (VESTA) software.

[0407] On the one hand, the calculated ESP diagrams of PEA2FAPb2I7 and PEA2ZnX4 show that -NH3 + The base ESP is almost the same ( Figure 18A and 18B ), which indicates that -NH3 + The radical-induced passivation effect may be similar for both passivators. It is also observed that the ESP of the halide anion in tetrahedral [ZnI4] is slightly more negative than that in octahedral [PbI6] ( Figure 18C and 18D ), which is consistent with the smaller electronegativity of Zn relative to Pb. This is conducive to the interaction between the halogen anions of PEA2ZnX4 and the positively charged V X The defects induce relatively stronger interactions, which contributes to a better passivation effect. On the other hand, compared with the tense connected octahedral [PbI6] structure in quasi-2DPEA2FAPb2I7, the isolated tetrahedral [ZnI4] structure in 0D PEA2ZnX4 is relatively relaxed ( Figure 19A and 19B ), which makes it easier for effective interactions to form between the passivating groups and defects. Another possible reason for the superiority of PEA2ZnX4 may be related to the modification of the interface energy level arrangement, which is discussed below.

[0408] Table 12. Lattice constants of PEA2FAPb2I7 and PEA2ZnI4.

[0409]

[0410] Kelvin probe force microscopy (KPFM) analysis was performed to explore the surface potential evolution of perovskite films with different capping materials. Figure 20AKPFM images of control 3D, 3D / PEAI, and 3D / PEA2ZnX4 stacked films are shown, where the same color scale represents the contact potential difference (CPD) between the tip and the sample surface. 3D / PEA2ZnX4 has the highest average CPD value ( Figure 20B ), indicating that the surface work function reduction induced by PEA2ZnX4 is more significant than that of the traditional Pb-based counterparts. In addition, ultraviolet photoelectron spectroscopy (UPS) analysis was performed to determine the Fermi level and valence band maximum (VBM) of the pristine 3D, 3D / PEAI, and 3D / PEA2ZnX4 stacked films ( Figure 20C ). It should be noted that the Fermi level mentioned here is actually the quasi-Fermi level. Subsequently, the conduction band minimum (CBM) was extrapolated through its relationship with the optical band gap, which was estimated from the UV-Vis spectra of the pristine 3D perovskite, PEA2FAPb2I7, and PEA2ZnICl3 ( Figure 21A –21C). It should be noted that in this case, the band gaps of the surface-covered components in the 3D / PEAI and 3D / PEA2ZnX4 stacks are roughly estimated based on the band gaps of the original PEA2FAPb2I7 and PEA2ZnICl3 films. This is because the initial covering PEAI and PEA2ZnX4 are primarily converted to PEA2FAPb2I7 and PEA2ZnICl3, respectively, after post-treatment (Table 3), as shown above.

[0411] Figure 22A and Figure 22B The charge transport at the nN homotype heterojunction interface is demonstrated. According to the Anderson model, the heterojunction between two contacting semiconductors can be divided into homotype and heterotype according to the conductivity type on both sides of the junction. The former involves two semiconductors with similar conductivity types, including nn type and pp type. In a specific nn homotype heterojunction, the electron affinity (χ), work function (φ) and band gap (E) of the two contacting semiconductors are determined. g ), there are four cases of energy band distribution, as shown below.

[0412] Case I:

[0413] χ1>χ2,φ1>φ2,χ1+E g1 <χ2+E g2

[0414] Case II:

[0415] χ1>χ2,φ1<φ2,χ1+E g1 <χ2+E g2

[0416] Case III:

[0417] χ1<χ2,φ1<φ2,χ1+E g1 >χ2+E g2

[0418] Case IV:

[0419] χ1>χ2,φ1>φ2,χ1+E g1 >χ2+E g2

[0420] The disclosed 3D / LD structure conforms to the band distribution of the first case of nn homotype heterojunction ( Figure 22C In this case, an accumulation layer is formed on the 3D side of the interface and a depletion layer is formed on the LD side of the interface, accompanied by a self-consistent quantum well at the interface ( Figure 22A According to various models proposed by Anderson and others, thermionic emission and quantum tunneling through the heterojunction barrier are two possible intrinsic mechanisms for charge transport at heterojunction interfaces.

[0421] As the obtained energy level diagram ( Figure 22C ), all Fermi levels of the 3D perovskite and the surface-capping components are closer to their CBMs, revealing n-type characteristics. Furthermore, the Fermi level of the surface-capping component in 3D / PEA2ZnX4 (-3.98 eV) is relatively higher than that of the surface-capping component in 3D / PEAI (-4.15 eV), and both are significantly enhanced relative to the control 3D perovskite (-4.42 eV), consistent with the KPFM results.

[0422] Importantly, the specific energy level arrangement in 3D / PEAI or 3D / PEA2ZnX4 facilitates the construction of nN homotypic heterojunctions with an additional built-in electric field directed from the surface to the bulk ( Figure 22C ), which results in V bi Enhanced, thereby enhancing V OC Due to the additional V bi Mainly dominated by the Fermi level difference at the junction, so 3D / PEA2ZnX4 can theoretically induce a stronger nN homotype heterojunction and produce a higher additional V by a larger Fermi level difference relative to conventional 3D / PEAI. bi The possible V of control, 3D / PEAI and 3D / PEA2ZnX4 PSCs were further investigated by light saturation method. bi The light saturation method is a non-destructive and non-invasive method for measuring the V bi Typically, for an ideal classical pn junction, V OC It can be calculated by the following formula:

[0423]

[0424] Among them, k, T, q, J ph and J th are the Boltzmann constant, absolute temperature, elementary charge, photocurrent density, and thermally generated current density (or dark current density). In fact, according to the E7 relationship, V OC It will not follow J th increases infinitely with the enhancement of V, especially at relatively high irradiances, because OC Also subject to the following restrictions:

[0425]

[0426] Among them, L p 、L n ,W,p n and n p They are respectively the hole diffusion length, the electron diffusion length, the depletion layer width, the hole concentration on the n-side of the junction, and the electron concentration on the p-side of the junction. p and τ n are the corresponding hole and electron lifetimes, respectively. g ph is the photo generation rate. p and τ n will be significantly shortened, so V OC cannot increase infinitely with the increase of light generation rate, and is expected to increase in the V bi Therefore, V bi According to the light saturation V OC To estimate. Here V OC It is determined by measuring the zero-position voltage when the output current of the device is zero.

[0427] As predicted, 3D / PEA2ZnX4 leads to a V bi The increase is greater ( Figure 23 ), which is consistent with V OC On the other hand, the specific built-in electric field at the nN heterojunction may cause holes to escape from the 3D perovskite surface, thereby reducing the hole concentration, which is beneficial to reduce the SRH recombination at the surface ( Figure 24 ), because the SRH recombination rate strongly depends on the surface concentration of minority carriers. This effect is usually called field-effect passivation in silicon solar cells. Therefore, due to the relatively larger built-in electric field at the corresponding nN isotype heterojunction, there may be stronger field-effect passivation in 3D / PEA2ZnX4, which is also the reason for the excellent passivation effect of PEA2ZnX4. In addition, the relatively deeper VBM of the surface covering component may also play a role in the interaction between the 3D perovskite layer and the C 60The hole barrier is caused between the electron transport layers, which effectively suppresses the C60 interface at the perovskite / C60 interface. 60 Undesirable recombination caused by the unfavorable tail state ( Figure 25 The slightly higher hole barrier in 3D / PEA2ZnX4 (0.42 eV, compared to 0.35 eV in 3D / Pb-LD) also contributes to a stronger suppression of charge recombination, thereby improving device performance.

[0428] Example 7: Device Performance and Stability of 3D / LD PSCs

[0429] The LD cap layer of the present disclosure has a smaller optimal thickness (about 20 nm, according to Figure 26 estimated), deposited via solution processing on a relatively rough 3D perovskite surface (Figures 11 and 37), which makes the LD capping layer likely to be discontinuous rather than conformal. Figure 22B As shown in Figure 3, thin and thick regions may coexist in the LD overlayer. Thin regions facilitate charge transport via tunneling. For thick regions, carriers can also diffuse to adjacent thin regions and transfer across the interface.

[0430] Considering that the relatively rough 3D perovskite surface may not be fully covered by the PEA2ZnX4 capping layer with a smaller optimal thickness (about 20nm), in order to further improve the device performance, the traditional surface passivation molecule TPPi was introduced into the best performing 3D / PEA2ZnX4 PSC (Figures 9, 11, 26 and 27). The chemical structure of the TPPi molecule is shown in Figure 9. Figure 28 As shown, its passivation effect is confirmed by the following: the k1 of 3D / TPPi films is reduced and τ is increased compared with the original 3D perovskite films (Figures 14 and 29, and Table 13), as well as the slightly increased PCE of 3D / TPPi PSCs (Table 14), which is also confirmed by other similar molecules. Thus, a maximum PCE of 24.1% is obtained, V OC 1.198V, J SC 24.0 mA cm -2 , FF is 83.9%, and the hysteresis is negligible ( Figure 30A The device exhibits an average stabilized power output (SPO) of 23.5% at the maximum power point (MPP). Figure 30B ) and showed good reproducibility in 103 independent cells with an average PCE of 22.9% ( Figure 30C and Table 15). By integrating the external quantum efficiency (EQE) spectrum J SC Verified the measured J SC ( Figure 30D), with a reasonable relative deviation of less than 2%. In addition, the PSC of the present invention was evaluated by the independent national research institute, the Solar Energy Research Institute of Singapore (SERIS), which provided a high-precision solar simulator for the PSC of the present invention, with a spectral mismatch factor close to ideal, 1.01 (in line with the IEC60904-9 standard). When measured in the reverse scanning direction, the certified PCE obtained was 23.25%, while when measured in the forward scanning direction, the certified area was 4.03mm. 2 Non-reflective black aperture (device active area 6.0mm 2 ), and the PCE obtained was 22.81%.

[0431] Table 13. Constants extracted from global fitting of the fluence-dependent TRPL decay dynamics of 3D perovskite films without or with TPPi passivation (see Figures 13 and 28).

[0432]

[0433] Table 14. Photovoltaic parameter statistics of control 3D PSCs without or with TPPi. 3D perovskite is Cs 15 .

[0434]

[0435] aData include the average and standard deviation calculated from 13 independent devices

[0436] Table 15. Photovoltaic parameter statistics of the target 3D / PEA2ZnX4 PSCs with additional TPPi passivation. The 3D perovskite and PEA2ZnX4 here are Rb5Cs 10 and PEA2ZnI2Cl2.

[0437]

[0438] aData include mean and standard deviation calculated from 103 individual devices

[0439] Finally, the operational stability of the 3D / LD PSC was tested based on the FP technology. The operational stability test was conducted in a N2-filled glove box (O2<10ppm, H2O<1.0ppm) at MPP and under white light emitting diode (LED) lighting conditions, with an effective irradiance equivalent to one solar intensity. It is worth noting that for the stability test, the PSC including Cs 153D perovskite and PEA2PbI4-PEA2ZnX4 mixed LD overlayer, this is considering that 3D / PEA2PbI4-PEA2ZnX4 PSC achieved comparable device performance relative to 3D / PEA2ZnX4 PSC (Table 16), which is attributed to the inherent superiority of PEA2ZnX4, as demonstrated above. Similar tests were performed on BA2PbI4, PMA2PbI4, PEA2CoX4, and BA2ZnX4, which also highlights the inherent superiority of PEA2ZnX4 (Tables 17 and 18). Therefore, after 1009 MPP runs of the target PSC, the initial PCE remained at 94.5%, which is a significant improvement compared to the control PSC ( Figure 31A and 31B ). In order to reveal the possible reasons for the stability improvement caused by the LD cover layer, the surface morphology and defect evolution of the relevant perovskite film were studied after aging the relevant perovskite film in air under the illumination of one times the solar intensity under unencapsulated conditions. Figure 32A 、 32B As shown in Figures 33A and 33B, the LD capping layer effectively inhibits the formation of pinholes on the surface of the 3D perovskite film. This may be due to the fact that the hydrophobic organic bulky cations in the LD capping layer structure block the penetration / erosion of H2O / O2 ( Figure 34 ).to this end, Figures 35A-35C The steady-state contact angles of deionized water on glass / PEA2ZnI4, glass / PEAI, and glass / ZnI2 films are shown. The contact angles of glass / PEA2ZnI4 and glass / PEAI films remained almost unchanged after one hour of measurement, indicating relatively good water repellency. In addition, it was found that the steady-state water contact angle of the glass / PEA2ZnI4 film was much larger than that of the glass / ZnI2 film, but slightly smaller than that of the glass / PEAI film, suggesting that the water repellency of PEA2ZnI4 may be derived from the presence of hydrophobic organic bulky cations (PEA2ZnI4). + ).

[0440] In addition, a relatively large decrease in the surface PL intensity of the control 3D perovskite film was observed ( Figure 36 ), which suggests that the LD capping layer may be beneficial in suppressing the generation of light-induced surface defects due to the robust interaction between the LD capping material and the 3D perovskite surface ( Figure 34 ).

[0441] It should be noted that some local degradation spots (e.g. Figure 36f), which may be due to incomplete coverage of the 3D perovskite surface by the LD layer. In order to further verify the role of the LD covering layer in improving device stability, the disclosed PSC was also subjected to an 85°C thermal stability test under ambient conditions or in N2 (refer to Example 3). When tested in air, the relatively rapid decrease in the PCE of the target device compared to that in N2 may be due to poor packaging. The initial average PCE of the control 3D device was (18.5±0.1)%. The initial average PCE of the target 3D / LD device tested under ambient conditions or in N2 was (20.1±0.1)% and (20.9±0.2)%, respectively. As expected, the target 3D / LD device exhibited enhanced thermal stability compared to the control 3D device ( Figure 37 ).

[0442] Table 16. Photovoltaic parameter statistics of target 3D / PEA2ZnX4 and 3D / PEA2PbI4-PEA2ZnX4 PSCs. Here, 3D perovskite and PEA2ZnX4 are Cs 15 and PEA2ZnI2Cl2.

[0443]

[0444] aData include the average and standard deviation calculated from 13 independent devices

[0445] Table 17. Photovoltaic parameter statistics of 3D / BA2PbI4, 3D / PMA2PbI4 and 3D / PEA2CoX4 PSCs based on the FP technology disclosed in this paper. The 3D perovskite here is Rb5Cs 10 .

[0446]

[0447] aData include the average and standard deviation calculated from 8 independent devices

[0448] Table 18. Photovoltaic parameter statistics of PSCs without or with different capping materials. Here, 3D perovskite, BA2ZnX4 and PEA2ZnX4 are Cs 15 , BA2ZnI2Cl2 and PEA2ZnI2Cl2.

[0449]

[0450]

[0451] aData include the average and standard deviation calculated from 13 independent devices

[0452] Although only representative PEA2PbI4 and PEA2ZnX4 are described in detail herein, the FP technology disclosed in this disclosure also demonstrates excellent performance on other commonly used LD capping materials (e.g., BA2PbI4 and PMA2PbI4, Table 17) as well as BA2ZnX4 (see Table 17). Figure 38 and Table 18) have wide applicability. 2+ In addition to cations, the FP technology disclosed herein also has the potential to be Co 2+ (PEA2CoX4)( Figure 39 and Table 17), Mn 2+ 、Cu 2+ Many other divalent metal ions, as well as Sb 3+ 、Bi 3+ and Al 3+ The use of trivalent metal ions such as ions in the LD layer opens channels, and these metal ions are expected to more effectively modulate the energy level arrangement and / or enhance the interface stability at the 3D / LD interface.

[0453] Industrial Applicability

[0454] The devices defined above may be used in perovskite optoelectronics, such as LEDs, lasers, photodetectors, radiation detectors, memristors, spintronic devices, phototransistors, transistors, LETs or FETs.

[0455] The methods defined above can also be used to develop superior LD capping materials from a large family of halometalates, including Pb-free capping materials, for more efficient and stable PSCs.

[0456] Obviously, after reading the above disclosure, various other modifications and adaptations of the present disclosure will be obvious to those skilled in the art without departing from the spirit and scope of the present disclosure. It is intended that all such modifications and adaptations fall within the scope of the appended claims.

Claims

1. Devices, including: a) A three-dimensional perovskite compound layer comprising a 1 )B(X 1 )3 three-dimensional perovskite compound, wherein: A 1 At least one ion selected from one or more elements of Group 1 of the Periodic Table, having R 1 -(NH x ) y + Organic cations of the structure and any mixture thereof, wherein, as long as the valence permits, R 1 is CH or alkyl, x is 2 or 3, and y is 1 or 2; B is at least one ion of one or more elements of Group 14 of the Periodic Table of the Elements or any mixture thereof; and X 1 is a halide ion or any mixture thereof; b) a covering material layer, which comprises a covering material and is disposed on the three-dimensional perovskite compound layer, wherein the covering material is selected from the group consisting of 2 )2M(X 2 )4、(A 2 )2(A 1 )M2(X 2 )7、(A 2 ) m M n (X 2 ) 3n+m or any mixture thereof; wherein: A 2 Is with R 2 -NH a + The ammonium cation of the structure, where R 2 is an optionally substituted C4-C 12 Alkyl, optionally substituted C3-C 12 cycloalkyl, optionally substituted arylalkyl, or any mixture thereof; M is at least one ion of one or more elements from Group 2, Group 3, Group 7, Group 8, Group 9, Group 10, Group 11, Group 12, Group 13 or Group 15 of the Periodic Table of the Elements, or any mixture thereof; X 2 is a halide ion or any mixture thereof; m is an integer 1, 2, 3, 4 or 5; n is an integer of 1 or 2; and a is 0 or an integer of 1, 2 or 3.

2. The device according to claim 1, wherein A 1 Selected from CH3NH3 + 、CH(NH2)2 + 、Cs + , Rb + and any mixture thereof, B is selected from Pb 2+ 、Sn 2+ 、Ge 2+ and any mixture thereof, and X 1 Selected from I - Br - 、Cl - 、F - and any mixture thereof.

3. The device according to claim 1 or 2, wherein the three-dimensional perovskite compound has Cs 0.15 FA 0.85 PbI 2.8 Cl 0.2 , Rb 0.05 Cs 0.10 FA 0.85 PbI 2.8 Cl 0.2 or Cs 0.05 (FA 0.83 MA 0.17 ) 0.95 Pb(I 0.83 Br 0.17 )3 structure, where MA is CH3NH3 + , and FA is CH(NH2)2 + .

4. A device according to any one of the preceding claims, wherein: A 2 selected from the group consisting of phenylethylammonium (PEA) ion, n-butylammonium (BA) ion, isobutylammonium ion, benzylammonium (PMA) ion, 1-naphthylmethylammonium (NMA) ion, and any mixture thereof; M is selected from Zn 2+ , Pb 2+ 、Co 2+ 、Mn 2+ 、Cu 2+ 、Sb 3+ 、Bi 3+ 、Al 3+ and any mixture thereof; or X 2 Selected from Cl - Br - , I - 、F - and any mixture thereof.

5. The device according to any one of the preceding claims, wherein the cover material layer has a single-crystal structure of the β-K2SO4 type, the β-K2PO3F type, cubic, orthorhombic or tetragonal type.

6. A device according to any one of the preceding claims, wherein the cover material layer is substantially free of Pb 2+ or Sn 2 + .

7. The device according to any one of the preceding claims, wherein the three-dimensional perovskite compound layer and the capping material layer are each independently annealed.

8. The device according to any one of the preceding claims, further comprising a hole transport layer comprising a hole transport material, wherein the three-dimensional perovskite compound layer is provided on the hole transport layer.

9. The device of claim 8, wherein the hole transport material is selected from the group consisting of poly(triarylamine) (PTAA), poly(3,4-ethylenedioxythiophene)polystyrenesulfonic acid (PEDOT:PSS), (2-(9H-carbazol-9-yl)ethyl)phosphoric acid (2PACZ), [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphoric acid (MeO-2PACZ), [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphoric acid (Me-4PACz), (2-(3,6-dimethyl-9H-carbazol-9-yl)ethyl)phosphoric acid (Me-2PACz), NiO, CuSCN, CuO, and any mixtures thereof.

10. The device according to claim 8 or 9, further comprising an electrode, wherein the hole transport layer is provided on the electrode.

11. The device of claim 10, wherein the electrode is selected from the group consisting of indium tin oxide (ITO), fluorine-doped tin oxide (FTO), and any mixture thereof. 12 . The device according to claim 1 , further comprising an electron transport layer comprising an electron transport material, the electron transport layer being disposed on the capping material layer.

13. The device according to claim 12, wherein the electron transport material is selected from C 60 / Bathocuproin ([6,6]-phenyl-C61 butyric acid methyl ester, BCP), 4-[3′-phenyl-3′H-cyclopropane[1,9](C 60 -I h )[5,6]fullerene-3′-yl]butyric acid methyl ester (PC61BM), (6,6)-phenyl C71 butyric acid methyl ester (PC71BM), 1',1",4',4"-tetrahydro-di[1,4]methylnaphtho[5,6]fullerene-C60 (ICBA), tin (IV) oxide, zinc oxide and any mixture thereof. 14 . The device according to claim 12 , further comprising a counter electrode disposed on the electron transport layer.

15. The device of claim 14, wherein the counter electrode comprises an element selected from the group consisting of gold, silver, platinum, aluminum, copper, carbon, and any mixture thereof. 16 . The device according to claim 8 , wherein the electron transport layer, the capping material layer, the three-dimensional perovskite compound layer, and the hole transport layer are independently in the form of films.

17. The device according to any one of claims 8 to 16, wherein the thickness of the counter electrode is in the range of about 100 nm to about 200 nm, the thickness of the electron transport layer is in the range of about 45 nm to about 75 nm, the thickness of the covering material layer is in the range of about 15 nm to 25 nm, the thickness of the three-dimensional perovskite compound layer is in the range of about 400 nm to about 700 nm, the thickness of the hole transport layer is in the range of about 20 nm to about 80 nm, or the thickness of the electrode is in the range of about 150 nm to about 300 nm.

18. The device of any preceding claim, wherein the device is an optoelectronic device, a photovoltaic cell, a solar cell, a light emitting diode (LED), a laser or a photodetector, a radiation detector, a memristor, a spintronic device, a phototransistor, a transistor, a light emitting transistor (LET), or a field effect transistor (FET).

19. A method for preparing a device according to any one of the preceding claims, comprising the steps of: i) providing a three-dimensional perovskite compound layer comprising a compound having the formula (A 1 )B(X 1 )3 three-dimensional perovskite compound, wherein: A 1 At least one ion selected from one or more elements of Group 1 of the Periodic Table, having R 1 -(NH x ) y + Organic cations of the structure and any mixture thereof, wherein, as long as the valence permits, R 1 is CH or alkyl, x is 2 or 3, and y is 1 or 2; B is at least one ion of one or more elements of Group 14 of the Periodic Table of the Elements or any mixture thereof; and X 1 is a halide ion or any mixture thereof; ii) having the formula M(X 2 ) z The metal halide and the metal halide having the formula (A 2 )(X 2 ) ammonium halide is mixed in a solvent to form a covering material solution, wherein A 2 Is with R 2 -NH a + The ammonium cation of the structure, where R 2 is an optionally substituted C4-C 12 Alkyl, optionally substituted C3-C 12 cycloalkyl, optionally substituted arylalkyl, or any mixture thereof; M is at least one ion of one or more elements from Group 2, Group 3, Group 7, Group 8, Group 9, Group 10, Group 11, Group 12, Group 13 or Group 15 of the Periodic Table of the Elements, or any mixture thereof; X 2 is a halide ion or any mixture thereof; a is 0 or the integer 1, 2 or 3; and z is 2 or 3; and iii) applying the covering material solution onto the three-dimensional perovskite compound layer to form a covering material layer comprising a covering material selected from the group consisting of: 2 )2M(X 2 )4、(A 2 )2(A 1 )M2(X 2 )7、(A 2 ) m M n (X 2 ) 3n+m a compound or any mixture thereof; wherein m is an integer of 1, 2, 3, 4 or 5; and n is an integer of 1 or 2.

20. The method of claim 19, wherein: The compound having the formula M(X 2 ) z The metal halide is selected from Pb(X 2 )2、Zn(X 2 )2、Sn(X 2 )2、Co(X 2 )2、Mn(X 2 )2、Cu(X 2 )2、Sb(X 2 )3、Bi(X 2 )3、Al(X 2 )3 and any mixture thereof; The compound having the formula (A 2 )(X 2 ) ammonium halide is selected from phenethylammonium halide (PEA (X 2 ))、n-butylammonium halide (BA(X 2 ))、isobutylammonium halide、benzylammonium halide (PMA(X 2 ))、1-naphthylmethylammonium halide (NMA(X 2 )) and any mixture thereof; or The solvent is selected from acetonitrile (ACN), acetone, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), methanol, tert-butanol, ethanol, isopropanol, tetrahydrofuran, methylamine, and any mixture thereof.

21. The method according to claim 19 or 20, wherein in the covering material solution, the 2 ) z The metal halide and the metal halide having the formula (A 2 )(X 2 ) of the ammonium halide are present in a molar ratio ranging from about 1:1 to about 1:

3.

22. The method according to any one of claims 19 to 21, wherein in the covering material solution, the 2 ) z The concentration of the metal halide in the solvent is in the range of about 5 mM to about 50 mM.

23. The method according to any one of claims 19 to 22, wherein the applying step comprises spin coating, spray coating, or slit coating the covering material solution on the three-dimensional perovskite compound layer, or immersing the three-dimensional perovskite compound layer in the covering material solution.

24. The method according to any one of claims 19 to 23, comprising the step of annealing the capping material layer onto the three-dimensional perovskite compound layer.

25. Use of the device of any one of claims 1 to 17 in an optoelectronic device, a photovoltaic cell, a solar cell, a light emitting diode (LED), a laser, a photodetector, a radiation detector, a memristor, a spintronic device, a phototransistor, a transistor, a light emitting transistor (LET), or a field effect transistor (FET).

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