Perovskite optoelectronic devices with isothiouronium passivation

Abstract

Perovskite optoelectronic devices are provided which comprise a perovskite layer comprising a perovskite; and isothiouronium passivating agents on a surface of the perovskite layer, wherein the isothiouronium passivating agents comprise an isothiouronium moiety, –SC(NR2)2 +, wherein each R is independently selected from H, alkyl, and aryl.

Description

Atty. Dkt. No. 00100-0395-PCTPEROVSKITE OPTOELECTRONIC DEVICES WITH ISOTHIOURONIUM PASSIVATION CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority to U. S. Provisional Patent Application No.63 / 683,003 that was filed August 14, 2024, the entire contents of which are incorporated herein by reference.REFERENCE TO GOVERNMENT RIGHTS

[0002] This invention was made with government support under 70NANB19H005 awarded by the National Institute of Standards and Technology. The government has certain rights in the invention.

[0003] This project has received funding from the Research Council of Lithuania (LMTLT), agreement No S-A-UEI-23-1 (22-12-2023).BACKGROUND

[0004] Perovskite solar cells (PSCs), because of their outstanding photovoltaic properties, simple and low-cost solution fabrication process, abundant precursors, and skyrocketing power conversion efficiency (PCE), have attracted tremendous attention and show great promise for scale-up and future commercialization. While the unprecedentedly high efficiency using perovskites is an astonishing achievement, issues relating to the long-term durability against atmospheric moisture and oxygen, heat, and light still raise concerns for the successful commercial application of PSC technology.SUMMARY

[0005] The present disclosure provides perovskite optoelectronic devices, including perovskite solar cells, comprising isothiouronium passivating agents. The isothiouronium passivating agents comprise an isothiouronium moiety. When incorporated into perovskite solar cells, it was found that illustrative isothiouronium passivating agents comprising one or more isothiouronium moieties exhibited very high PCEs (e.g., greater than 25%). The isothiouronium passivating agents and compositions comprising the isothiouronium passivating agents are also provided.Atty. Dkt. No. 00100-0395-PCT

[0006] An embodiment 1 is a perovskite optoelectronic device comprising a perovskite layer comprising a perovskite; and isothiouronium passivating agents on a surface of the perovskite layer, wherein the isothiouronium passivating agents comprise an isothiouronium moiety, SC(NR2)2, wherein each R is independently selected from H, alkyl, and aryl.

[0007] An embodiment 2 is according to embodiment 1, wherein the sulfur atom of the isothiouronium moiety is covalently bound to a carbon of a R’ group of the isothiouronium passivating agents.

[0008] An embodiment 3 is according to any of embodiments 1-2, wherein each R in the isothiouronium moiety is H.

[0009] An embodiment 4 is according to embodiment 1, wherein the isothiouronium passivating agents comprise the isothiouronium moiety and an additional isothiouronium moiety -SC(NR2)2+, wherein each R in the additional isothiouronium moiety is independently selected from H, alkyl, and aryl.

[0010] An embodiment 5 is according to embodiment 4, wherein the sulfur atom of the isothiouronium moiety is covalently bound to a carbon of a R’ group of the isothiouronium passivating agents.

[0011] An embodiment 6 is according to embodiment 1, wherein the isothiouronium passivating agents are selected from formula X+(R2N)2CS--R’--SC(NR2)2+X', wherein each R is independently selected from H, alkyl, and aryl; R’ is selected from alkyl and aryl; and each X is an independently selected counter ion.

[0012] An embodiment 7 is according to embodiment 6, wherein R’ is a linear alkyl.

[0013] An embodiment 8 is according to embodiment 7, wherein the linear alkyl has from 2 to 26 carbon atoms.

[0014] An embodiment 9 is according to any of embodiments 6-8, wherein each R in each isothiouronium moiety is H.

[0015] An embodiment 10 is according to embodiment 1, wherein the isothiouronium passivating agents are selected from formula X+(R2N)2CS-R’-A, wherein each R is independently selected from H, alkyl, and aryl; R’ is selected from alkyl and aryl; X is a counter ion; and A is selected from COOH, B(OH)2, Si(OH)3, SO2OH, and PO(OH)2.

[0016] An embodiment 11 is according to embodiment 10, wherein R’ is a linear alkyl.Atty. Dkt. No. 00100-0395-PCT

[0017] An embodiment 12 is according to embodiment 11, wherein the linear alkyl has from 2 to 26 carbon atoms.

[0018] An embodiment 13 is according to any of embodiments 10-12, wherein each R in the isothiouronium moiety is H.

[0019] An embodiment 14 is according to any of embodiments 10-13, wherein A is COOH or PO(OH)2.

[0020] An embodiment 15 is according to embodiment 14, wherein R’ is a linear alkyl and each R in the isothiouronium moiety is H.

[0021] An embodiment 16 is according to any of embodiments 1-15, wherein the perovskite optoelectronic device is configured as a perovskite solar cell comprising a hole transport layer, an electron transport layer, the perovskite layer between the hole transport layer and the electron transport layer, and the isothiouronium passivating agents on the surface of the perovskite layer.

[0022] An embodiment 17 is according to embodiment 16, wherein the isothiouronium passivating agents are located at an interface formed between the electron transport layer and the perovskite layer, an interface between the hole transport layer and the perovskite layer, or at both interfaces.

[0023] An embodiment 18 is a composition comprising isothiouronium passivating agents and a perovskite, wherein the isothiouronium passivating agents comprise an isothiouronium moiety, SC(NR2)2, wherein each R is independently selected from H, alkyl, and aryl.

[0024] An embodiment 19 is an isothiouronium passivating agent selected from ’ X+(R2N)2CS-R’-PO(OH)2 or X+(R2N)2CS-R’-COOH, wherein each R is independently selected from H, alkyl, and aryl; R’ is selected from alkyl and aryl; and X is a counter ion.

[0025] An embodiment 20 is according to embodiment 19, wherein R’ is a linear alkyl and each R in the isothiouronium moiety is H.

[0026] Other principal features and advantages of the disclosure will become apparent to those skilled in the art upon review of the following drawings, the detailed description, and the appended claims.Atty. Dkt. No. 00100-0395-PCTBRIEF DESCRIPTION OF THE DRAWINGS

[0027] Illustrative embodiments of the disclosure will hereafter be described with reference to the accompanying drawings.

[0028] FIG. 1 shows illustrative isothiouronium passivating agents. One of the isothiouronium moieties on one of the agents is labeled.

[0029] FIG. 2 shows a cross-sectional view of a schematic of an illustrative perovskite solar cell.

[0030] FIG. 3A shows a cross-sectional view of an illustrative poerovskite solar cell. 2,2’ -ethylenediiso thiouronium iodide (di-isothiouronium) was used at the interface formed between the perovskite layer (perovskite) and the electron transport layer (ETL). 2-(4-phosphonobutyl)isothiouronium bromide (phosphonoalkyl isothiouronium) was used at the interface formed between the perovskite layer and the hole transport layer (HTL). FIG. 3B shows the current density voltage (J-V) characteristics of the solar cell. FIG. 3C shows the operating stability of the encapsulated solar cell under 1-sun equivalent illumination at 85°C in ambient air as compared to a control solar cell without isothiouronium passivating agents.DETAILED DESCRIPTION

[0031] Perovskite optoelectronic devices are provided which comprise a perovskite layer and a plurality of isothiouronium passivating agents thereon. The isothiouronium passivating agents may be located at an interface formed between the perovskite layer and another material layer of the optoelectronic device. The isothiouronium passivating agents may be characterized as being in the form of an isothiouronium passivating layer at this interface.

[0032] Although the isothiouronium passivating agents may be used in a variety of perovskite optoelectronic devices (e.g., light-emitting diodes, lasers, detectors, sensors), in embodiments, the perovskite optoelectronic device is a perovskite solar cell. A basic embodiment of a perovskite solar cell 200 is shown in FIG. 2. Such a perovskite solar cell 200 may comprise a hole transport layer 202 over a substrate 204, an electron transport layer 206, a perovskite layer 208 between the hole transport layer 202 and the electron transport layer 206, and a plurality of isothiouronium passivating agents. The isothiouronium passivating agents may be located at an interface 210 formed between the perovskite layer 208 and the electron transport layer 206, at an interface 212 formed between the perovskiteAtty. Dkt. No. 00100-0395-PCTlayer 208 and the hole transport layer 202, or both. The isothiouronium passivating agents may be characterized as being in the form of an isothiouronium passivating layer at either (or both) of these interfaces 210, 212. A contact layer may be disposed over the electron transport layer 206. Each of these components of the perovskite solar cell, as well as additional components that may be used, are described in further detail below.

[0033] An isothiouronium passivating agent is a chemical compound comprising an isothiouronium moiety. Illustrative isothiouronium passivating agents are shown in FIG. 1 and in the Example, below. The isothiouronium moiety may be represented by -SC(NR2)2+(or more precisely ~SC(NR2)(NR2)+) wherein each R is independently selected from H, alkyl, and aryl. In embodiments, each R in the isothiouronium moiety is H such that the isothiouronium moiety may be represented by ~SC(NH2)2+(or more precisely, - SC(NH2)(NH2)+). The represents a covalent bond to the remainder of the isothiouronium passivating agent. As shown in FIG. 1, this covalent bond may be a carbon-sulfur bond, wherein the carbon may be a carbon atom of an alkyl group or an aryl group. Generally, this covalent bond is not a metal-sulfur bond. Thus, compounds comprising an isothiouronium moiety wherein the sulfur atom is bound to a metal, e.g., a transition metal, may be excluded. Compounds which may be excluded as isothiouronium passivating agents include N-(4-bromophenyl)thiourea and Cu(thiourea) complexes.

[0034] In embodiments, the isothiouronium passivating agent comprises two isothiouronium moieties. Such isothiouronium passivating agents may be represented by+(R2N)2CS-R’-SC(NR2)2+, wherein R has been defined above and R’ may be selected from alkyl and aryl. (The more precise version of the isothiouronium moiety described above also applies here.) In embodiments, R’ is a linear alkyl, e.g., ethyl, propyl, butyl, hexyl, dodecyl, hexadecyl, etc. As noted above, in embodiments, each R in each isothiouronium moiety is H.

[0035] In embodiments, the isothiouronium passivating agent comprises a single isothiouronium moiety and an additional functional moiety (other than the disclosed isothiouronium moieties). The additional functional moiety is capable of binding to a conductive oxide, e.g., fluorine doped tin oxide (FTO), indium doped tin oxide (ITO), etc. Such isothiouronium passivating agents may be represented by+(R N)2CS~R’~A, wherein R has been defined above, R’ may be selected from alkyl and aryl, and A is the additional functional moiety. (The more precise version of the isothiouronium moiety described above also applies here.) Illustrative additional functional moieties A include -COOH, -B(OH)2, -Atty. Dkt. No. 00100-0395-PCTSi(OH)3, –SO2OH, –PO(OH)2. The represents a covalent bond to the R’ group, e.g., to a carbon atom of the R’ group. In embodiments, R’ is a linear alkyl, e.g., ethyl, propyl, butyl, hexyl, dodecyl, hexadecyl, etc. As noted above, in embodiments, each R in the isothiouronium moiety is H.

[0036] In embodiments, the isothiouronium passivating agent comprises a single isothiouronium moiety and a phosphoric acid moiety. Such isothiouronium passivating agents may be represented by+(R2N)2CS-R’-PO(OH)2, wherein R has been defined above and R’ may be selected from alkyl and aryl. (The more precise version of the isothiouronium moiety described above also applies here.) In embodiments, R’ is a linear alkyl, e.g., ethyl, propyl, butyl, hexyl, dodecyl, hexadecyl, etc. As noted above, in embodiments, each R in the isothiouronium moiety is H.

[0037] In embodiments, the isothiouronium passivating agent comprises a single isothiouronium moiety and a carboxylic acid moiety. Such isothiouronium passivating agents may be represented by (R2N)2CS R’-COOH, wherein R has been defined above and R’ may be selected from alkyl and aryl. (The more precise version of the isothiouronium moiety described above also applies here.) In embodiments, R’ is a linear alkyl, e.g., ethyl, propyl, butyl, hexyl, dodecyl, hexadecyl, etc. As noted above, in embodiments, each R in the isothiouronium moiety is H.

[0038] It is understood that in any of the cationic moieties above, a counter ion(s) may be present which may be presented by X‘. Illustrative counter ions may be selected from halides, e.g., T, Br, etc. In embodiments, the counter ion(s) is T. Br‘ may be excluded as a counter ion. The phrase “isothiouronium passivating agent” encompasses protonated and deprotonated versions thereof as well as salts thereof.

[0039] Illustrative isothiouronium passivating agents include 2,2'-ethylenediisothiouronium halide; 2,2'-propylenediisothiouronium halide; 2-(2-phosphonoethyl)isothiouronium halide; 2-(3-phosphonopropyl)isothiouronium halide; 2-(4-phosphonobutyl)isothiouronium halide; 2-(6-phosphonohexyl)isothiouronium halide; 2-(12-phosphonododecyl)isothiouronium halide; 2-(4-phosphonobutyl)isothiouronium halide; 2-(6-phosphonohexyl)isothiouronium halide; 2-(12-phosphonododecyl)isothiouronium halide; 2-(6-carboxyhexyl)isothiouronium halide; 2-(12-carboxydodecyl)isothiouronium halide; 2-(16-carboxyhexadecyl)isothiouronium halide; 2-(20-carboxyicosyl)isothiouronium halide.Atty. Dkt. No. 00100-0395-PCT

[0040] Regarding alkyl, this term may refer to a linear, branched, or cyclic alkyl group in which the number of carbons may range from, e.g., 1 to 26, 1 to 20, 1 to 18, 1 to 16, 1 to 12, 1 to 8, 1 to 6, 1 to 4, 1 to 3, or 1 to 2. A cyclic alkyl group may be referred to as a cycloalkyl group. The alkyl group may be unsubstituted, by which it is meant the alkyl group contains no heteroatoms. An unsubstituted alkyl group encompasses an alkyl group in which one or more bonds to a carbon(s) or hydrogen(s) are replaced by a bond to an unsubstituted aromatic ring, e.g. as in benzyl. The alkyl group may be substituted, by which it is meant an unsubstituted alkyl group in which one or more bonds to a carbon(s) or hydrogen(s) are replaced by a bond to non-hydrogen and non-carbon atoms.

[0041] Regarding aryl, this term refers to a monocyclic aryl group having one aromatic ring (e.g., phenyl) or a polycyclic group having more than one aromatic ring (e.g., two, three, etc. rings). Monocyclic aryl groups may be unsubstituted or substituted as described above with respect to alkyl groups. Regarding polycyclic groups, neighboring aromatic rings may be fused or unfused. The aromatic rings of a polycyclic group may be unsubstituted or substituted as described above with respect to monocyclic aryl groups.

[0042] A single type of isothiouronium passivating agent or multiple, different types of isothiouronium passivating agents may be used. Various amounts of the isothiouronium passivating agent may be used, including to achieve a desired power conversion efficiency (PCE), e.g., a maximum PCE, for a perovskite solar cell containing the isothiouronium passivating agents.

[0043] The isothiouronium passivating agents may be directly synthesized in a one-step reaction refluxing a halogenated substrate, e.g., an alkylhalide or alkyldihalide, with thiourea. An illustrative procedure based on the alkylation of thiourea is provided in the Example, below. Any of the additional functional moieties described above, e.g., -COOH, -B(OH)2, - Si(OH)3, --SO2OH, -PO(OH)2, may be provided by the halogenated substrate.

[0044] The perovskite of the perovskite layer refers to a chemical compound having a perovskite structure such as ABX3. In embodiments, A is a protonated amine or an alkali metal ion; B is a divalent metal ion; and X is an anion capable of bonding to B. A variety of protonated amines may be used, e.g., a primary ammonium, a secondary ammonium, a tertiary ammonium, a quaternary ammonium, or an iminium. Suitable illustrative protonated amines include, e.g., NH4+(ammonium); CH₃NH₃⁺ (methylammonium); CH(NH2)2+(formamidinium); (CH3)2NH2+(dimethylammonium); (CH3CH2)NH3+(ethylammonium);Atty. Dkt. No. 00100-0395-PCT(NH2)3C+(guanidinium); and (CH3)4N+(tetramethylammonium). A variety of alkali metal ions may be used, e.g., Cs+. A variety of divalent metal ions may be used, e.g., a posttransition metal or a metalloid such as Sb3+, Bi3+, Ge2+, Sn2+, or Pb2+. A variety of anions may be used, e.g., a halide such as F’, Cl’, Br, or I’, and pseudo halides such as SCN’, OCN’, or BF4’.

[0045] The term “perovskite” (as well as the formula ABX3) encompasses alloys including more than one type of A in varying relative amounts (provided the sum of the amounts is about 1); more than one type of B in varying relative amounts (provided the sum of the amounts is about 1); more than one type of X in varying relative amounts (provided the sum of the amounts is about 3); and combinations thereof.

[0046] For perovskite solar cells, various materials may be used in the hole transport layer (e.g., carbazole-based self-assembled monolayers (SAMs), poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT: PSS)) and the electron transport layer (e.g., buckminsterfullerene, Ceo, and its derivatives). Any other material layers typically used in perovskite solar cells may be included, e.g., a substate (e.g., glass, indium tin oxide, fluorine-doped tin oxide), contacts (e.g., various metals), a hole blocking layer (e.g., bathocuproine), an electron blocking layer, etc.

[0047] Perovskite solar cells comprising the present isothiouronium passivating agents may be configured according to a particular architecture such as an inverted (pin) architecture in which the perovskite solar cell is illuminated through the electron transport layer. The perovskite solar cell may be a single junction or a multijunction device (e.g., a tandem device).

[0048] Perovskite solar cells comprising the present isothiouronium passivating agents are characterized by high power conversion efficiencies (PCEs) which may be tested as described in the Example, below.

[0049] Various methods may be used to fabricate the present perovskite optoelectronic devices, including those described in the Example, below. In embodiments, the perovskite layer is provided by depositing (e.g., via spin coating) a perovskite precursor solution comprising the perovskite and a solvent, followed by annealing. The isothiouronium passivating agents may be included in the perovskite precursor solution. As noted above, during this process, the isothiouronium passivating agents may assemble at an interfaceAtty. Dkt. No. 00100-0395-PCTformed between the perovskite layer and an overlying or underlying material layer of the perovskite optoelectronic device.

[0050] Methods of using the present perovskite optoelectronic devices are also provided. The methods comprise illuminating any of the disclosed perovskite optoelectronic devices with light to generate charge carriers, and collecting the charge carriers.

[0051] The isothiouronium passivating agents themselves are also encompassed by the present disclosure, including compositions comprising the isothiouronium passivating agents. For example, in embodiments, a composition is provided which comprises any of the disclosed isothiouronium passivating agents and any of the disclosed perovskites.EXAMPLE

[0052] Isothiouronium salt preparation by alkylation of thiourea was used to synthesize several isothiouronium passivating agents as set forth below. Thiourea (1.1 or 2.2 mmol) was dissolved in isopropanol (10 ml), and 1 mmol of the corresponding alkylhalide or alkyldihalide was added. The reaction mixture was stirred at 80-85 °C for 3-4 hours. After cooling the reaction mixture, the solvent was distilled off with a vacuum rotary evaporator. The resulting crystals were dissolved in methanol and precipitated in diethyl ether. The precipitate was filtered, washed with diethyl ether, and dried to obtain isothiouronium halide salt in quantitative yield. Fifteen compounds that were synthesized and confirmed by ’H NMR are listed below.J NH2+X’H2N+NH2UR X - ► R S NH2General ProcedureNH2+rH2N^fS^'^^S^NH2NH2+r2, 2 '-ethylenediisothiouronium iodide

[0053] ’1H NMR (400 MHz, DMSO-d6) δ 9.05 (s, 8H), 3.38 (d, 4H).13C NMR (101 MHz, DMSO-d6) δ 168.80, 29.55.Atty. Dkt. No. 00100-0395-PCTNH2+r NH2*IH2N S S NH22,2'-propylenediisothiouronium iodide

[0054] ’HNMR (400 MHz, DMSO-^) 58.98 (d, J= 42.1 Hz, 8H), 3.19 (t, 14.8, 7.6 Hz, 4H), 2.02 - 1.83 (m, 2H).13C NMR (101 MHz, DMSO-rf6) 3 169.36, 28.64, 28.33.NH2+rH2N¥S^S NH2NH2I"2,2'-butylenediisothiouronium iodide

[0055] ‘HNMR (400 MHz, DMSO-^) 58.95 (s, 8H), 3.31 (t, 4H), 1.81 (p, 4H).13C NMR (101 MHz, DMSO-t / 6) 5 169.99, 29.85, 27.65.OHH2N S^^OHNH2+Br 62-(2-phosphonoethyl)isothiouronium bromide

[0056] ’H NMR (400 MHz, DMSO- «) 58.86 (d, 4H), 3.39 - 3.01 (m, 2H), 2.19 - 1.49 (m, 2H).13C NMR (101 MHz, DMSO-tfe) 5 170.02, 27.59, 25.47 (dc-p, J = 13.4 Hz).NH2+BrH2N S62-(3-phosphonopropyl)isothiouronium bromide

[0057] ‘H NMR (400 MHz, DMSO-^) 89.84 - 8.64 (m, 4H), 3.29 (t, 2H), 1.80 (t, 2H), 1.64 (p, J = 16.7, 7.6 Hz, 2H).l3C NMR (101 MHz, DMSO- e) 5 169.57, 30.18, 24.76 (dc-p, J = 17.0 Hz).2-(4-phosphonobutyl)isothiouronium bromide

[0058] ’HNMR (400 MHz, DMSO-t / fi) 89.03 (d, J= 59.5 Hz, 4H), 3.16 (dd, 19.5, 12.6 Hz, 2H), 1.77 - 1.63 (m, 2H), 1.64 - 1.46 (m, 4H).13C NMR (101 MHz, DMSO-cfc) 8 170.51, 30.15, 29.84, 27.26, 22.32 (dc-p, 4.4 Hz).Atty. Dkt. No. 00100-0395-PCTH2N?HOHP nNH2+Br O2-( 6-phosphonohexyl)isothiouronium bromide

[0059] ¹H NMR (400 MHz, DMSO-d₆) δ 8.98 (s, 4H), 3.13 (t, J = 7.2 Hz, 2H), 1.58 (t, J = 7.0 Hz, 2H), 1.51 - 1.29 (m, 8H).13C NMR (101 MHz, DMSO-d₆) δ 169.82, 29.38, 29.22, 26.83, 22.62, 22.57.2-(12-phosphonododecyl)isothiouronium bromide

[0060] ‘HNMR (400 MHz, DMSO-cfe) 58.97 (d, J = 51.8 Hz, 4H), 3.13 (t, J = 7.2 Hz, 2H), 1.58 (t, J= 7.1 Hz, 2H), 1.52 - 1.40 (m, 4H), 1.38 - 1.14 (m, 16H).13C NMR (101 MHz, DMSO-d₆) δ 169.88, 30.11, 29.97, 28.95, 28.91, 28.83, 28.67, 28.34, 28.23, 27.75, 26.88, 22.75, 22.71.H2N^S^X'\^^OHNH2+T 62-(4-phosphonobutyl)isothiouronium iodide

[0061] ‘HNMR (400 MHz, DMSO-cfe) 58.96 (d, J= 80.0 Hz, 4H), 3.14 (t, J = 7.2 Hz, 2H), 1.69 (t, 2H), 1.56 (t, J= 10.3 Hz, 4H).13C NMR (101 MHz, DMSO-d₆) δ 169.82, 29.55, 27.26, 25.90, 21.67 (dc-p, 4.4 Hz).2-(6-phosphonohexyl)isothiouronium iodide

[0062] ‘HNMR (400 MHz, DMSO-t / o) 58.96 (d, J = 51.5 Hz, 4H), 3.12 (t, 2H), 1.76 (t, 2H), 1.58 (t, 2H), 1.46 (t, 2H), 1.39 - 1.22 (m, 4H).13C NMR (101 MHz, DMSO-d₆) δ 169.82, 30.05, 29.38, 28.16, 27.38, 26.77, 22.57 (dc-p, 4.7 Hz).2-( 12-phosphonododecyl)isothiouronium iodide

[0063] 1H NMR (400 MHz, DMSO-d₆) δ 8.94 (d, J = 57.1 Hz, 4H), 3.12 (t, J = 6.9 Hz, 2H), 1.58 (t, 2H), 1.46 (t, J = 10.1 Hz, 4H), 1.34 - 1.21 (m, 16H).13C NMR (101 MHz,Atty. Dkt. No. 00100-0395-PCTDMSO-d₆) δ 169.85, 30.15, 30.12, 29.99, 28.97, 28.93, 28.85, 28.69, 28.35, 28.28, 27.77, 26.91, 22.76 (dc-p, J = 4.6 Hz).H2NCOOKNH2+I2-(6-carboxyhexyl)isothiouronium iodide

[0064] ’H NMR (400 MHz, DMSO-d₆) δ 12.00 (s, 1H), 8.94 (d, J = 42.1 Hz, 4H), 3.12 (t, J = 7.3 Hz, 2H), 2.19 (t, J = 7.3 Hz, 2H), 1.58 (p, J = 7.3 Hz, 2H), 1.48 (p, J = 7.3 Hz, 2H), 1.40 – 1.21 (m, 4H). ¹³C NMR (101 MHz, DMSO-d₆) δ 174.47, 169.82, 33.53, 30.07, 28.24, 27.88, 27.52, 24.28.H2N., SCOOHNH2+r2-(l 2-carboxydodecyl)isothiouronium iodide

[0065] 'H NMR (400 MHz, DMSO-d₆) δ 11.71 (s, 1H), 8.95 (s, 4H), 3.12 (t, J = 7.3 Hz, 2H), 2.18 (t, J = 7.3 Hz, 2H), 1.58 (p, J = 7.2 Hz, 2H), 1.52 – 1.43 (m, 2H), 1.39 – 1.30 (m, 2H), 1.31 – 1.14 (m, 14H). ¹³C NMR (101 MHz, DMSO-d₆) δ 174.54, 169.81, 33.67, 30.10, 28.97, 28.94, 28.93, 28.87, 28.76, 28.56, 28.37, 28.33, 27.78, 24.50.H2N COOH2-( 16-carboxyhexadecyl)isothiouronium iodide

[0066] lH NMR (400 MHz, DMSO-d₆) δ 11.96 (s, 1H), 8.93 (d, J = 51.6 Hz, 4H), 3.12 (t, J = 7.3 Hz, 2H), 2.18 (t, J = 7.3 Hz, 2H), 1.58 (p, J = 7.3 Hz, 2H), 1.52 – 1.43 (m, 2H), 1.38 – 1.30 (m, 2H), 1.30 – 1.14 (m, 22H). ¹³C NMR (101 MHz, DMSO-d₆) δ 174.52, 169.82, 33.66, 30.11, 29.07, 29.05, 29.03, 29.02, 28.97, 28.93, 28.88, 28.76, 28.56, 28.38, 28.32, 27.79, 24.50.H2NCOOHNH2+r2-(20-carboxyicosyl)isothiouronium iodide

[0067] 'H NMR (400 MHz, DMSO-d₆) δ 11.95 (s, 1H), 8.93 (d, J = 54.7 Hz, 4H), 3.12 (t, J = 7.3 Hz, 2H), 2.18 (t, J = 7.3 Hz, 2H), 1.58 (p, J = 7.2 Hz, 2H), 1.52 – 1.41 (m, 2H), 1.39 – 1.29 (m, 2H), 1.30 – 1.12 (m, 30H). ¹³C NMR (101 MHz, DMSO-d₆) δ 174.51, 169.82,Atty. Dkt. No. 00100-0395-PCT33.66, 30.10, 29.05, 29.03, 29.00, 28.98, 28.93, 28.88, 28.76, 28.56, 28.38, 28.33, 27.80, 24.50

[0068] Perovskite solar cells were fabricated as follows: Fluorine-doped tin oxide (FTO) glasses were cleaned using acetone and isopropanol in an ultrasonic bath, followed by ultraviolet ozone treatment in ambient air for 30 minutes. The hole transport layer (HTL) was NiOx / [4-(3,6-Dimethyl-9H-carbazol-9-yl)butyl]phosphonic Acid (Me-4PACz). The NiOx solution (5 mg / mL in deionized water and isopropanol (3:1 v / v)) was spin-coated on the substrates at 3,000 r.p.m. for 30 s in air. Then, a 0.5 mg / mL Me-4PACz in ethanol solution was spin-coated on NiOx at 4,000 r.p.m. for 30 s, followed by annealing at 100°C for 10 min. For bottom passivation, 0.5 mg / mL 2-(4-phosphonobutyl)isothiouronium bromide in ethanol was spin-coated on the substrate at 4,000 r.p.m. for 30 s, followed by annealing at 100°C for 10 min. Cso.o5MAo.o5FAo.9oPbl3 perovskite precursors were dissolved with 5 mol% MAPbCh in a mixed dimethylformamide and dimethyl sulfoxide DMSO solvent (4: 1 v / v) at a concentration of 1.6 M. The perovskite solution was fdtered by a 0.22 pm polytetrafluoroethylene (PTFE) membrane and spin-coated at 1000 r.p.m for 10 s (acceleration rate 500 r.p.m. / s) and 5000 r.p.m. for 35 s (acceleration rate 2000 r.p.m. / s), respectively. At the 20 s of the second step, 150 pL anisole was dropped as the antisolvent. The films were then annealed at 100°C for 15 min. For top passivation, 1 mg / mL 2,2'-ethylenediisothiouronium iodide in isopropanol was filtered and spin-coated on the perovskite films at 5,000 r.p.m. for 30 s, followed by annealing at 100°C for 5 min. For electron transport layer (ETL), 30 nm Ceo was thermally evaporated on the perovskite films under a high vacuum of ~10-7Torr. The substrates were then transferred to the atomic layer deposition (ALD) system (Savannah) to deposit 20 nm SnCh at 90 °C using tetrakis(dimethylamino) tin (IV) and water precursors. Finally, 140 nm Cu was thermally evaporated as back electrodes under a high vacuum of ~10-7Torr. A schematic of the solar cell is shown in FIG. 3A. The test results for the device are shown in FIGS. 3B and 3C. The dual-passivation strategy yielded a power conversion efficiency (PCE) of 26.5% and markedly enhanced operating stability at 85 °C, demonstrating the capability of isothiouronium-based passivators for high-performance PSCs.

[0069] Additional information is found in U. S. Provisional Patent Application No.63 / 683,003 that was filed August 14, 2024, the entire contents of which are incorporated herein by reference.Atty. Dkt. No. 00100-0395-PCT

[0070] The word "illustrative" is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as "illustrative" is not necessarily to be construed as preferred or advantageous over other aspects or designs. Further, for the purposes of this disclosure and unless otherwise specified, "a" or "an" means "one or more.”

[0071] The foregoing description of illustrative embodiments of the disclosure has been presented for purposes of illustration and of description. It is not intended to be exhaustive or to limit the disclosure to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the disclosure. The embodiments were chosen and described in order to explain the principles of the disclosure and as practical applications of the disclosure to enable one skilled in the art to utilize the disclosure in various embodiments and with various modifications as suited to the particular use contemplated. It is intended that the scope of the disclosure be defined by the claims appended hereto and their equivalents.

[0072] If not already included, all numeric values of parameters in the present disclosure are proceeded by the term “about” which means approximately. This encompasses those variations inherent to the measurement of the relevant parameter as understood by those of ordinary skill in the art. This also encompasses the exact value of the disclosed numeric value and values that round to the disclosed numeric value.

[0073] The term “type” as used herein refers to chemical formula such that a single type means the same chemical formula and different type means different chemical formula. Similarly, use of “more” as in “one or more” and the like refers to use of different types of the relevant entity.

[0074] Terms such as “comprising” and the like may be replaced with terms such as “consisting” and the like.

[0075] In recognition of the inherent nature of chemical synthesis, throughout the present disclosure, terms and phrases such as “absence,” “free,” “does not comprise,” etc. encompass, but do not require a perfect absence of the referenced entity.

Claims

Atty. Dkt. No. 00100-0395 -PCTWHAT IS CLAIMED IS:

1. A perovskite optoelectronic device comprising a perovskite layer comprising a perovskite; and isothiouronium passivating agents on a surface of the perovskite layer, wherein the isothiouronium passivating agents comprise an isothiouronium moiety, -SC(NR2)2+. wherein each R is independently selected from H, alkyl, and aryl.

2. The perovskite optoelectronic device of claim 1, wherein the sulfur atom of the isothiouronium moiety is covalently bound to a carbon of a R’ group of the isothiouronium passivating agents.

3. The perovskite optoelectronic device of claim 1, wherein each R in the isothiouronium moiety is H.

4. The perovskite optoelectronic device of claim 1, wherein the isothiouronium passivating agents comprise the isothiouronium moiety and an additional isothiouronium moiety -SC(NR2)2+, wherein each R in the additional isothiouronium moiety7is independently selected from H, alkyl, and aryl.

5. The perovskite optoelectronic device of claim 4, wherein the sulfur atom of the isothiouronium moiety is covalently bound to a carbon of a R’ group of the isothiouronium passivating agents.

6. The perovskite optoelectronic device of claim 1, wherein the isothiouronium passivating agents are selected from formula X (R2N)2CS R’ SC(NR2)2+X", wherein each R is independently selected from H, alkyl, and aryl; R’ is selected from alkyl and aryl; and each X is an independently selected counter ion.

7. The perovskite optoelectronic device of claim 6, wherein R’ is a linear alky l.

8. The perovskite optoelectronic device of claim 7. wherein the linear alkyl has from 2 to 26 carbon atoms.

9. The perovskite optoelectronic device of claim 6, wherein each R in each isothiouronium moiety is H.Atty. Dkt. No. 00100-0395 -PCT10. The perovskite optoelectronic device of claim 1, wherein the isothiouronium passivating agents are selected from formula X+(R2N)2CS–R'–A, wherein each R is independently selected from H, alkyl, and aryl: R’ is selected from alky l and aryl: X is a counter ion; and A is selected from COOH, B(OH)2, Si(OH)3, SO2OH, and PO(OH)2.

11. The perovskite optoelectronic device of claim 10, wherein R' is a linear alkyl.

12. The perovskite optoelectronic device of claim 11, wherein the linear alkyl has from 2 to 26 carbon atoms.

13. The perovskite optoelectronic device of claim 10, wherein each R in the isothiouronium moiety7is H.

14. The perovskite optoelectronic device of claim 10, wherein A is COOH or PO(OH)2.

15. The perovskite optoelectronic device of claim 14, wherein R’ is a linear alky l and each R in the isothiouronium moiety7is H.

16. The perovskite optoelectronic device of claim 1 configured as a perovskite solar cell comprising a hole transport layer, an electron transport layer, the perovskite layer between the hole transport layer and the electron transport layer, and the isothiouronium passivating agents on the surface of the perovskite layer.

17. The perovskite optoelectronic device of claim 16, wherein the isothiouronium passivating agents are located at an interface formed between the electron transport layer and the perovskite layer, an interface between the hole transport layer and the perovskite layer, or at both interfaces.

18. A composition comprising isothiouronium passivating agents and a perovskite, wherein the isothiouronium passivating agents comprise an isothiouronium moiety, -SC(NR2)2+, wherein each R is independently selected from H, alkyl, and aryl.

19. An isothiouronium passivating agent selected from X (R2N)2CS-R’-PO(OH)2 or X ( R.2N)2CS- ’-COOH. wherein each R is independently selected from H. alkyl, and aryl; R is selected from alkyl and aryl; and X is a counter ion.Atty. Dkt. No. 00100-0395 -PCT20. The isothiouronium passivating agent of claim 19, wherein R' is a linear alkyl and each R in the isothiouronium moiety is H.

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