Hole-selective contact material, photoelectric conversion device, and polycyclic aromatic hydrocarbon compound

Abstract

To provide a hole-selective contact material for PSCs with long-term stability. [Solution] The hole-selective contact material includes a polycyclic aromatic hydrocarbon compound having a structure with multiple aromatic hydrocarbon rings, each of which is fused with at least one other aromatic hydrocarbon ring, and at least one anchor group attached to the structure directly or via a linking group.

Description

[Technical Field]

[0001] The present disclosure relates to hole-selective contact materials, photovoltaic devices, and polycyclic aromatic hydrocarbon compounds. [Background technology]

[0002] Perovskite solar cells (PSCs) are promising photovoltaic devices due to the unique optoelectronic properties of metal halide perovskite materials, such as a high optical absorption coefficient in the visible light region, a long charge carrier diffusion length, solution processability, and suitability for large-area solar cell modules. In recent years, inverted pin-structure PSCs, which are compatible with tandem solar cells and are less susceptible to moisture and oxygen than conventional nip-structure devices, have achieved significant advances in power conversion efficiency (PCE). This significant improvement in efficiency is largely due to the careful design of interfacial passivation layers, optimized perovskite compositions, and the development of novel hole-selective contacts. In particular, the design of the hole-selective contact on the light-emitting side of the device significantly affects not only the efficiency but also the long-term operational stability of inverted PSCs. Such design is currently the subject of intensive research.

[0003] P-type organic semiconductors are often used as hole-selective contacts in inverted PSCs because they can be processed at low temperatures and their energy levels can be tuned to improve alignment with the perovskite layer. To date, electron-donating aromatic systems such as triarylamines, carbazoles, and polythiophenes have been used as π-conjugated building blocks for hole-selective molecules.

[0004] Poly(bis(4-phenyl)(2,4,6-trimethylphenyl)amine) (PTAA) is a triarylamine-based hole-selective contact that has been commonly used to fabricate high-performance inverted PSCs (Non-Patent Documents 1 and 2).

[0005] PTAA derivatives functionalized with pyridine anchor groups (p-PY) have been investigated as hole-selective contacts (Non-Patent Document 3).

[0006] Furthermore, carbazole-based molecules such as 2PACz and MeO-2PACz with phosphonic acid anchor groups have been investigated as conformal hole-selective contacts for fabricating highly efficient inverted PSCs (Non-Patent Document 4).

[0007] In addition, a hole-selective molecule EADR04 having a π-conjugated linker between the carbazole core and the anchor group has also been studied (Non-Patent Document 5).

[0008] Furthermore, donor-acceptor (DA) conjugated structures of hole-selective molecules have been investigated to improve their inherent photostability (Non-Patent Document 6). [Prior art documents] [Non-patent literature]

[0009] [Non-Patent Document 1] Y. Wang, L. Duan, M. Zhang, Z. Hameiri, X. Liu, Y. Bai, X. Hao, Sol. RRL 2022, 6, 2200234. [Non-patent document 2] T. Wu, LK Ono, R. Yoshioka, C. Ding, C. Zhang, S. Mariotti, J. Zhang, K. Mitrofanov, X. Liu, H. Segawa, R. Kabe, L. Han, YB Qi, Energy Environ. Sci. 2022, 15, 4612. [Non-patent document 3] R. Chen, S. Liu, X. Xu, F. Ren, J. Zhou, X. Tian, Z. Yang, X. Guanz, Z. Liu, S. Zhang, Y. Zhang, Y. Wu, L. Han, Y. B. Qi, W. Chen, Energy Environ. Sci. 2022. [Non-Patent Document 4] A. Al-Ashouri, A. Magomedov, M. Ros, M. Jost, M. Talaikis, G. Chistiakova, T. Bertram, J. A. Marquez, E. Kohnen, E. Kasparavicius, S. Levcenco, L. Gil-Escrig, C. J. Hages, R. Schlatmann, B. Rech, T. Malinauskas, T. Unold, C. A. Kaufmann, L. Korte, G. Niaura, V. Getautis, S. Albrecht, Energy Environ. Sci. 2019, 12, 3356. [Non-Patent Document 5] E. Aktas, N. Phung, H. Kobler, D. A. Gonzalez, M. Mendez, I. Kafedjiska, S.-H. Turren-Cruz, R. Wenisch, I. Lauermann, A. Abate, E. Palomares, Energy Environ. Sci. 2021, 14, 3976. [Non-Patent Document 6] S. Zhang, R. Wu, C. Mu, Y. Wang, L. Han, Y. Wu, W.-H. Zhu, ACS Materials Letters 2022, 4, 1976. [Summary of the Invention] [Problems to be Solved by the Invention]

[0010] Despite intensive research, inverted PSCs currently have a shorter operational lifetime than conventional PSCs, and therefore new design concepts for the hole-selective contact are urgently needed in order to achieve high photostability and good compatibility with solar cell modules. [Means for solving the problem]

[0011] As a result of extensive research, the present inventors have discovered a new strategy for designing photostable and scalable hole-selective contact materials based on polycyclic aromatic hydrocarbon compounds for PSCs with long-term stability, particularly for inverted PSCs with long-term stability.

[0012] The gist of the present disclosure is as follows. [1] A hole-selective contact material comprising a polycyclic aromatic hydrocarbon compound, The polycyclic aromatic hydrocarbon compound has a structure having a plurality of aromatic hydrocarbon rings, each of which is fused with at least one other aromatic hydrocarbon ring, and at least one anchor group is attached to the structure directly or via a linking group, to form a hole-selective contact material. [2] The hole-selective contact material of [1] or [2], wherein the anchor group is selected from the group consisting of carboxylic acid groups, carboxylate groups, cyanoacrylic acid groups, cyanoacrylate groups, pyridine groups, phosphonic acid groups, tetracyanate groups, perylenedicarboxylic anhydride groups, 2-hydroxybenzonitrile groups, 8-hydroxyquinoline groups, pyridine-N-oxide groups, 3-hydroxy-N-methylpyridinium groups, catechol groups, hydroxamate groups, sulfonic acid groups, acetylacetonate groups, boronic acid groups, nitro groups, tetrazole groups, rhodamine groups, rhodamine-3-acetic acid groups, salicylic acid groups, aldehyde groups, carbamate groups, unsubstituted or substituted amino groups, unsubstituted or substituted ammonium groups, halogen atoms, and imine groups. [3] The hole-selective contact material according to [1] or [2], wherein the linking group is selected from the group consisting of an alkylene group, an alkenylene group, an alkynylene group, a cycloalkylene group, an arylene group, and a heteroarylene group. [4] The hole-selective contact material according to any one of [1] to [3], wherein the structure having a plurality of aromatic hydrocarbon rings has an absorption edge in the range of 350 to 550 nm. [5] The hole-selective contact material according to [4], wherein the structure having a plurality of aromatic hydrocarbon rings has an absorption edge in the range of 400 to 500 nm. [6] The hole-selective contact material according to any one of [1] to [5], wherein the plurality of aromatic hydrocarbon rings comprises 3 to 16 aromatic hydrocarbon rings. [7] The hole-selective contact material according to any one of [1] to [6], wherein the plurality of aromatic hydrocarbon rings are a plurality of benzene rings. [8] The hole-selective contact material according to any one of [1] to [7], wherein the structure is benzo[rst]pentaphene. [9] The hole-selective contact material according to any one of [1] to [8], wherein the polycyclic aromatic hydrocarbon compound contains at least one solubility-enhancing group.

[10] The hole-selective contact material according to [9], wherein the solubility-enhancing group is selected from the group consisting of an alkyl group, an alkoxy group, an aryl group, and an ester group.

[11] A photoelectric conversion device comprising the hole-selective contact material according to any one of [1] to

[10] .

[12] The photoelectric conversion device according to

[11] , wherein the photoelectric conversion device is a perovskite solar cell.

[13] A polycyclic aromatic hydrocarbon compound represented by formula (1): [ka] In the above formula, R1, R2, R3, R4, R9, R 10 , R 11 and R 12are independently selected from a hydrogen atom, a C1-C12 alkyl, and a C1-C12 alkoxy; R5 and R8 are independently R a and -arylene-R a Selected from (R a is a carboxylic acid group, a carboxylate group, or a carbamate group), R6, R7, R 13 and R 14 is a hydrogen atom. [Effects of the Invention]

[0013] The present disclosure provides hole-selective contact materials for PSCs with long-term stability, particularly inverted PSCs with long-term stability. The use of specific hole-selective contact materials in PSCs provides fast and uniform hole extraction and stabilizes organic components at the buried perovskite interface. These advantages result in higher device efficiencies than commonly used triphenylamine- and carbazole-based hole-selective contacts. [Brief explanation of the drawings]

[0014] [Figure 1] a) 1H NMR spectrum (400 MHz, 298 K) and 13C NMR spectrum (101 MHz, 298 K) of BPP using CD2Cl2. [Figure 2] a) 1H NMR spectrum (400 MHz, 298 K) and b) 13C NMR spectrum (101 MHz, 298 K) of SA-BPP using CD2Cl2. [Figure 3] High-resolution mass spectra of a) BPP and b) SA-BPP (top: calculated isotope distribution pattern, bottom: experimental isotope distribution pattern). [Figure 4] 1H NMR spectrum (400 MHz, 298 K) of BPP-Boc in CD2Cl2. [Figure 5]HOMO and LUMO orbital distributions using the DFT method in the Gaussian 09 program. [Figure 6] Properties of BPP and SA-BPP molecules are shown. (a) Chemical structures of BPP and SA-BPP molecules and a schematic diagram of the SA-BPP hole-selective contact that can form bonds with both the ITO substrate and the perovskite layer in an inverted PSC. (b) FTIR spectra of pure SA-BPP, an SA-BPP-ITO blend, and an SA-BPP-PbI2 blend. (c) Band structures of BPP and SA-BPP films coated on an ITO substrate determined by UPS and LEIPS measurements. (d) Energy offset between the HOMO of BPP and SA-BPP and the VBM of the perovskite absorber. The red dashed line indicates the EF position. [Figure 7] Hole-selective contacts and the subsequently deposited perovskite thin films. (a-c) Surface potential mapping profiles over a 50 μm × 50 μm area for (a) ITO / MeO-2PACz, (b) ITO / BPP, and (c) ITO / SA-BPP samples. Statistical distributions of potential are also shown, demonstrating the homogeneity of these thin films. (d-f) Top-view SEM images of perovskite thin films deposited on the hole-selective contacts of (d) MeO-2PACz, (e) BPP, and (f) SA-BPP. (g-i) Cross-sectional SEM images of perovskite thin films deposited on the hole-selective contacts of (g) MeO-2PACz, (h) BPP, and (i) SA-BPP. [Figure 8] a-c) Surface potential mapping profiles in a 50 μm × 50 μm area of ​​perovskite thin films deposited on (a) MeO-2PACz, (b) BPP, and (c) SA-BPP substrates. [Figure 9] XRD patterns of perovskite thin films grown on various hole-selective contacts. The diffraction peaks are 14.0°, 20.1°, 23.8°, 28.1°, and 32.0° associated with the (100), (110), (111), (200), and (210) planes of the perovskite phase. [Figure 10]Carrier dynamics at the hole-selective contact / perovskite interface are shown. (a-c) Delay-time-dependent transient absorption spectra of (a) MeO-2PACz / perovskite film, (b) BPP / perovskite film, and (c) SA-BPP / perovskite film deposited on glass substrates at pump-probe delay times of 30-500 ps. (d-f) PL mapping profiles over a 100 μm × 100 μm area of ​​perovskite thin films deposited on (d) MeO-2PACz substrate, (e) BPP substrate, and (f) SA-BPP substrate. [Figure 11] a-c) Transient absorption dynamics of the ground-state bleaching peak of perovskite thin films with (a) MeO-2PACz, (b) BPP, and (c) SA-BPP contacts on glass substrates. [Figure 12] a–c) Total DOS plots of defect-containing FAPbI3(100) slabs with (a) no passivation, (b) BPP passivation, and (c) SA-BPP passivation, showing the band-edge trap states. The bottom panel shows the HOMO charge distribution plots for the system. [Figure 13] The photostability of the hole-selective contact and the relative interface with the perovskite layer are shown. (a-c) High-resolution XPS spectra in the C 1s region of solid films of (a) MeO-2PACz, (b) SA-BPP, and (c) PTAA coated on ITO substrates before and after 100 hours of exposure to simulated 1-sun light in dry N2. (d-f) In situ MS contour profiles (m / z = 1-200 amu) of (d) MeO-2PACz / perovskite film, (e) SA-BPP / perovskite film, and (f) PTAA / perovskite film coated on ITO glass. Irradiation with simulated 1-sun light was initiated 15 minutes after the MS measurement, for a total exposure time of 120 minutes. (g) The mechanism of degradation that may occur at the perovskite / hole-selective contact interface under 1-sun irradiation conditions is shown. [Figure 14]Current mapping profiles of a–c) fresh ITO / MeO-2PACz, ITO / SA-BPP, and ITO / PTAA films before aging, and d–f) films after 100 h of continuous aging under 1-sun irradiation in a N2 atmosphere, with the applied bias fixed at 1.0 V. It is noteworthy that the hole-selective contacts used for current mapping measurements are thicker than those used to fabricate inverted PSCs, which allows for a better understanding of the conductivity changes under operating conditions. [Figure 15] a) Schematic of the in situ mass spectrometry (MS) system we designed to investigate light-induced degradation at the hole-selective contact / perovskite interface. b-d) The partial pressure of gas products released from perovskite thin films deposited on (b) MeO-2PACz substrate, (c) SA-BPP substrate, and (d) PTAA substrate versus irradiation time. [Figure 16] a) Electrostatic potential (ESP) mapping profiles of MeO-2PACz, SA-BPP, and PTAA molecules containing three triarylamine units calculated using DFT methods. b) Electron deformation density plots of MeO-2PACz, SA-BPP, and PTAA monomers interacting with FA+ cations. The cation-π interaction energies were calculated to be -0.47 eV for MeO-2PACz, -1.08 eV for SA-BPP, and -0.28 eV for PTAA. [Figure 17]Photovoltaic performance of inverted perovskite solar cells and modules. (a) Cross-sectional SEM image of an SA-BPP-based inverted PSC. (b) JV curves of compact inverted PSCs (champion devices) using MeO-2PACz, BPP, and SA-BPP hole-selective contacts. (c) EQE spectra of MeO-2PACz and SA-BPP-based champion devices. (d) Photograph of a 5 cm × 5 cm solar cell module using an SA-BPP hole-selective contact. (e) JV curve of an SA-BPP-based solar cell module with an aperture area of ​​22.4 cm2. The inset shows the module structures for the P1, P2, and P3 patterns. (f) PL intensity mapping profile of a perovskite thin film coated on a 5 cm × 5 cm ITO (P1 pattern) / SA-BPP substrate. [Figure 18] a) Design patterns of solar cell modules on a 5 cm x 5 cm ITO substrate. b) Optical microscope images of the P1, P2, and P3 patterns, with a geometric fill factor (GFF) of 95.8%. [Figure 19] a) Operational stability test system for PSC. The temperature of the test device was monitored by a thermocouple (blue line), and a continuous N2 flow was supplied to the sample chamber throughout the operation. b) Solar spectrum emitted by the xenon white light source used for stability measurements. [Figure 20] The operational stability of inverted perovskite solar cells and modules is shown. (a-b) Champion device operational stability tests were performed on (a) a small solar cell and (b) a 5 cm x 5 cm solar cell module in an N2-filled chamber at 45 °C under a fixed bias near the initial maximum power point. [Figure 21] a) Cross-sectional SEM image of a PTAA-based inverted PSC. b) JV curve of a miniature inverted PSC with a PTAA hole-selective contact for operational stability measurement. [Figure 22]High-resolution XPS a) O 1s spectra and b) Sn 3d spectra of PCBM / C60 films without and with an ALD-SnO2 protective layer. c) Optical microscope images of solar cell modules (patterns P1-P3) without and with an ALD-SnO2 protective layer before and after 100 hours of simulated 1-sun irradiation. [Figure 23] (a) Forward and reverse J-V curves of a 0.1 cm inverted PSC with a BPP-Br hole-selective contact. (b) Operational stability test of a 0.1 cm inverted PSC with a BPP-Br hole-selective contact at 45 °C in an N-filled chamber. [Figure 24] (a) Forward and reverse J-V curves of a 0.1 cm inverted PSC with a BPP-MeOPA hole-selective contact. (b) Operational stability test of a 0.1 cm inverted PSC with a BPP-MeOPA hole-selective contact at 45 °C in an N-filled chamber. [Figure 25] (a) Forward and reverse J-V curves of a 0.1 cm inverted PSC with a BPP-Boc hole-selective contact. (b) Operational stability test of a 0.1 cm inverted PSC with a BPP-Boc hole-selective contact at 45 °C in an N-filled chamber. DETAILED DESCRIPTION OF THE INVENTION

[0015] The technology of the present disclosure will be described in detail below.

[0016] (term) An "alkyl group" may be straight-chain or branched and generally contains 1 to 20 carbon atoms. Examples of "alkyl groups" include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, sec-pentyl, tert-pentyl, neopentyl, amyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl. The "alkenyl group" may be straight-chain or branched, and generally has 2 to 20 carbon atoms. Examples of the "alkenyl group" include vinyl, allyl, butenyl, butadienyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, and dodecenyl. The "alkynyl group" may be straight-chain or branched, and generally has 2 to 20 carbon atoms. Examples of the "alkynyl group" include ethynyl, propargyl, butynyl, pentynyl, hexynyl, heptynyl, octynyl, nonyl, decynyl, undecynyl, and dodecynyl. The "cycloalkyl group" may be a monocyclic group or a polycyclic group, and the number of carbon atoms can generally be 3 to 30. Examples of the "cycloalkyl group" include cyclopentyl, cyclohexyl, cycloheptyl, adamantyl, methylcyclohexyl, and ethylcyclohexyl. The "alkylene group" may be straight-chain or branched, and the number of carbon atoms can generally be 1 to 20. Examples of the "alkylene group" include methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, and dodecylene. The "alkenylene group" may be straight-chain or branched, and the number of carbon atoms may generally be 2 to 20. Examples of the "alkenylene group" include vinylene, propenylene, butenylene, butadienylene, octenylene, decenylene, and dodecenylene. The "alkynylene group" may be linear or branched, and the number of carbon atoms may generally be 2 to 20. Examples of the "alkynylene group" include an ethynylene group, a propynylene group, a butynylene group, a pentynylene group, a hexynylene group, a heptynylene group, an octynylene group, a nonynylene group, a decynylene group, an undecynylene group, and a dodecynylene group. An "alkoxy group" is alkyl-O-, and the above description of the alkyl group applies to the alkyl moiety. Examples of the "alkoxy group" include methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, and allyloxy. A "cycloalkylene group" is a divalent group corresponding to a cycloalkyl group. An "aryl group" is a monovalent aromatic hydrocarbon group, and the number of carbon atoms can generally be 6 to 20. Examples of "aryl groups" include phenyl, naphthyl, biphenyl, and phenanthryl. A "heteroaryl group" is a monovalent aromatic heterocyclic group, and the number of ring atoms can generally be 4 to 10. The heteroatom can be nitrogen, oxygen, or sulfur. Examples of "heteroaryl groups" include pyridinyl, furanyl, and thiophenyl. An "arylene group" is a divalent group corresponding to an aryl group. A "heteroarylene group" is a divalent group corresponding to the heteroaryl group. "Halogen atom" includes fluorine, chlorine, bromine and iodine atoms.

[0017] (Structure having multiple aromatic hydrocarbon rings) A specific hole-selective contact material according to the present disclosure includes a polycyclic aromatic hydrocarbon compound. The polycyclic aromatic hydrocarbon compound has a structure with multiple aromatic hydrocarbon rings, each of which is fused with at least one other aromatic hydrocarbon ring. That is, each of the aromatic hydrocarbon rings shares two adjacent carbon atoms with at least one other aromatic hydrocarbon ring. This specific structure is advantageous for tunable optoelectronic properties and stability against light and heat.

[0018] A structure in which all aromatic hydrocarbon rings are benzene rings may correspond to a substructure contained in monolayer graphene. Such a structure is also called a graphene-like conjugated molecule or graphenoid. Graphene-like conjugated structures are advantageous in providing charge carrier mobility due to the electron delocalization caused by the large π-extended conjugated structure.

[0019] The number of aromatic hydrocarbon rings is one or more, preferably two or more. The number of aromatic hydrocarbon rings may be 16 or less. The optical absorption edge of a structure having multiple aromatic hydrocarbon rings may be 700 nm or less. To ensure a suitable optical absorption edge, preferably in the range of 350 to 550 nm, the number of aromatic hydrocarbon rings is preferably 3 to 16, more preferably 4 to 12, and even more preferably 4 to 8. For the following reasons, an absorption edge of 350 to 550 nm is preferred for a structure having multiple aromatic hydrocarbon rings, which corresponds to an optical energy gap of 2.25 to 3.54 eV. The electron energy gap may be proportional to the optical energy gap of the structure, but must be small enough to ensure efficient charge transport through the hole-selective contact material of the present disclosure, while not being too small to avoid significant absorption of sunlight. An absorption edge of 400 to 500 nm is more preferred. The absorption edge can be determined using the methods described in the following references: JCS Costa et al., “Optical band gaps of organic semiconductor materials”, Optical Materials, Volume 58, August 2016, pp. 51-60

[0020] Examples of structures in which all aromatic hydrocarbon rings are benzene rings include anthracene, phenanthrene, pyrene, tetracene, chrysene, perylene, benzo[a]anthracene, benzo[a]pyrene, dibenzo[a,h]anthracene, benzo[ghi]perylene, pentaphene, benzo[rst]pentaphene, coronene, anthanthrene, triphenylene, trinaphthylene, hexaperihexabenzocoronene, naphtho[8,1,2-bcd]perylene, naphtho[1,2,3,4-ghi]perylene, dibenzo[b,k]chrysene, benzo[c]picene, Benzo[a]pentacene, Benzo[a]coronene, Phenanthrene[5,4,3,2-efghi]perylene, Benzo[pqr]naphtho[8,1,2-bcd]perylene, Benzo[vwx]hexaphene, Benzo[c]naphtho[2,1,8-qra]tetracene, Dibenzo[h,rst]pentaphene, Naphtho[8,1,2-abc]coronene, Pyranthrene, Tribenzo[de,kl,rst]pentaphene, Tetrabenzo[de,hi,mn,qr]tetracene, Tribenzo[f,k,m]tetraphene, Dibenzo[a,c]pentacene, Diben zo[a,l]pentacene, heptaphene, ovalene, dinaphtho[2,1,8,7-defg:2',1',8',7'-opqr]pentacene, dinaphtho[2,1,8,7-defg:2',1',8',7'-ijkl]pentaphene, dibenzo[a,j]coronene, naphtho[1,2-a]coronene, naphtho[8,1,2-hij]hexaphene, dibenzo[fg,ij]phenanthrol[2,1,10,9,8,7-pqrstuv]pentaphene, peryleneno[3,2,1,12-pqrab]perylene, benzo[rst]dinaphtho[2,1,8 ,7-defg:2',1',8',7'-ijkl]pentaphene, dinaphtho[8,1,2-abc:8',1',2'-jkl]coronene, dinaphtho[8,1,2-abc:2',1',8'-klm]coronene, naphtho[2',1',8',7':4,10]anthra[1,9,8-abcd]coronene, tetrabenzo[def,lm,qrs,yz]pyranthrene, hexabenzo[bc,ef,hi,kl,no,qr]coronene, and tetrabenzo[bc,ef,o,uv]phenanthro[2,1,10,9-hijk]ovalene.

[0021] Certain structures may contain rings other than benzene rings, such as acenaphthylene, acenaphthene, fluorene, fluoranthene, benzo[b]fluoranthene, benzo[j]fluoranthene, benzo[k]fluoranthene, benzo[c]fluorene, indeno[1,2,3-cd]pyrene, and corannulene.

[0022] Additionally, the polycyclic aromatic hydrocarbons described in the following references can also be used in the structures of the present disclosure. R. Rieger et al., “polycyclic aromatic hydrocarbons as model cases for structural and optical studies”, Journal of Physical Organic Chemistry, Volume 23, Issue 4 p. 315-325 (2010) M. Kastler et al., “From Armchair to Zigzag Peripheries in Nanographenes”, J. Am. Chem. Soc. 2006, 128, 29, 9526-9534 J. Prakash et al., “Simultaneous Quantification of Multiple Polycyclic Aromatic Hydrocarbons in Aqueous Media using Micelle Assisted White Light Excitation Fluorescence”, Scientific Reports volume 10, Article number: 8921 (2020). In addition, the substituted or unsubstituted polycyclic aromatic hydrocarbon compounds disclosed in WO 2020 / 070085 can also be used in the structures of the present disclosure.

[0023] The above structures can be prepared by the "PEX" reaction described in the following references: The polycyclic aromatic hydrocarbon compounds disclosed in these references can also be utilized in the structures of the present disclosure. D. Lungerich, et al., “Dehydrative π-extension to nanographenes with zig-zag edges”, Nature Communications volume 9, Article number: 4756 (2018) M. Feofanov, et al., “Modular Approach to the Synthesis of Two-Dimensional Angular Fused Acenes”, Org. Lett. 2020, 22, 5, 1698-1702.

[0024] These structures can be prepared by the "APEX" reaction and acetylene cyclization reaction described in the following references: The polycyclic aromatic hydrocarbon compounds disclosed in these references can also be used in the structures of the present disclosure. K. Ozaki et al., “One-shot K-region-selective annulative π-extension for nanographene synthesis and functionalization”, Nature Communication, volume 6, Article number:6251(2015). Tse-An Chen, et al., “Synthesis of Polyaromatic Hydrocarbons from Bis(biaryl)diynes: Large PAHs with Low Clar Sextets”, Chemistry-A European Journal, Volume 17, Issue 29, 2011, Pages 8023-8027.

[0025] A combination of zigzag and armchair edges is preferred because it provides an excellent platform for adjusting energy levels. An example of such a combination of zigzag and armchair edges is benzo[rst]pentaphene, although other structures may also be used.

[0026] (anchor group) The polycyclic aromatic hydrocarbon compound according to the present disclosure preferably includes at least one anchor group attached to the structure described above, either directly or via a linking group, which acts as an anchor to the surroundings when the hole-selective contact material according to the present disclosure is used. Examples of anchor groups include carboxylic acid groups, carboxylate groups, cyanoacrylic acid groups, cyanoacrylate groups, pyridine groups, phosphonic acid groups, tetracyanate groups, perylenedicarboxylic anhydride groups, 2-hydroxybenzonitrile groups, 8-hydroxyquinoline groups, pyridine-N-oxide groups, 3-hydroxy-N-methylpyridinium groups, catechol groups, hydroxamate groups, sulfonic acid groups, acetylacetonate groups, boronic acid groups, nitro groups, tetrazole groups, rhodamine groups, rhodamine-3-acetic acid groups, salicylic acid groups, aldehyde groups, carbamate groups, unsubstituted or substituted amino groups, unsubstituted or substituted ammonium groups, halogen atoms, and imine groups. These may be used alone or in combination of two or more. Substituted amino and ammonium groups include amino and ammonium groups having one or more substituents, such as alkyl and aryl groups which may be further substituted with alkoxy groups. Substituted amino groups include dialkylamino, bis(methoxyphenyl)amino, and the like.

[0027] Examples of the linking group include an alkylene group, an alkynylene group, a cycloalkylene group, an arylene group, and a heteroarylene group, as well as combinations of two or more of these groups.

[0028] The anchor groups are preferably carboxylic acid and carboxylate groups. The carboxylic acid group includes a group represented by -COOH, which may be in the form of a salt. The salt may be an inorganic salt or an organic salt. Examples of the salt include alkali metal salts (e.g., -COONa, -COOK, -COOCs), ammonium salts, etc. The cation of the salt may be a quaternary ammonium such as methylammonium, imidazolium, dimethylammonium, formamidinium, guanidinium, and aziridinium. The carboxylate group includes a group represented by -COOR, where R is an alkyl group or an aryl group, preferably methyl, ethyl, or phenyl. These groups are preferably bonded to the above structure directly or via an arylene group (preferably a phenylene group).

[0029] Preferably, the compound has 1 to 8 anchor groups. More preferably, the number of anchor groups is 2 to 6. When two or more anchor groups are present, they may be the same or different. The anchor groups are preferably the same. The anchor groups may be attached to the same aromatic hydrocarbon ring or to different aromatic hydrocarbon rings. They are preferably attached to different aromatic hydrocarbon rings. In certain embodiments where a stronger anchor is desired, the polycyclic aromatic hydrocarbon compound has 2 to 4 anchor groups. In certain embodiments, the polycyclic aromatic hydrocarbon compound includes one or two bidentate or polydentate anchor groups.

[0030] The anchor group can be introduced into the compound by known methods.

[0031] (Solubility improving group) The specific polycyclic aromatic hydrocarbon compound according to the present disclosure may contain a solubility-enhancing group bonded to the above structure to improve its solubility in a solvent. Examples of the solubility-enhancing group include an alkyl group (preferably C1-C12 alkyl), an alkoxy group (preferably C1-C12 alkoxy), and an ester group. These may be used alone or in combination of two or more. Examples of the ester group include a group having -C(=O)O-, such as a carboxylate group. The polycyclic aromatic hydrocarbon compound may contain one to four solubility-enhancing groups. In certain embodiments, the polycyclic aromatic hydrocarbon compound contains two solubility-enhancing groups. In certain embodiments where greater solubility is desired, the polycyclic aromatic hydrocarbon compound contains three or four solubility-enhancing groups. On the other hand, if the anchor group also promotes solubility, sufficient solubility may be obtained without the addition of a solubility-enhancing group. Examples include anchor groups having alkyl, alkoxy, or ester groups. Furthermore, when the anchor group does not contain an ester group or is a methyl carboxylate ester group or an ethyl carboxylate ester group, the solubility-enhancing group may be a C3-C10 alkyl carboxylate group. Examples of C3-C10 alkyl carboxylate groups include t-Bu carboxylate, pentyl carboxylate, hexyl carboxylate, heptyl carboxylate, and octyl carboxylate groups.

[0032] When two or more anchor groups are present, the solubility-enhancing groups may be the same or different, but are preferably the same.

[0033] Solubility-enhancing substituents can be introduced into the compounds by known methods.

[0034] (Other Substituents) The polycyclic aromatic hydrocarbon compound according to the present disclosure may have a substituent other than the anchor group, the linking group to the anchor group, and the solubility-enhancing group.

[0035] (Polycyclic aromatic hydrocarbon compounds) Preferred polycyclic aromatic hydrocarbon compounds for use in the hole-selective contact material according to the present disclosure include compounds represented by formula (1): [ka] In the above formula, R1~R 14are each independently selected from a hydrogen atom, an anchor group, a linking group having an anchor group, or a solubility-enhancing group; However, at least one of them is an anchor group or a linking group substituted with an anchor group.

[0036] Examples of the anchor group, linking group, and solubility-enhancing group are as described above. The anchor group and the solubilizing group are preferably not too close to each other, for example, they are bonded to non-adjacent carbon atoms. The anchor group and the solubilizing group may be bonded to different hydrocarbon aromatic rings.

[0037] Represented by formula (1), R1, R2, R3, R4, R9, R 10 , R 11 and R 12 are independently selected from a hydrogen atom and a solubility-enhancing group; R5 and R8 are independently selected from an anchor group and a linking group substituted by an anchor group; R6, R7, R 13 and R 14 is a hydrogen atom is preferred. For example, in the case of the compound represented by formula (1), R1, R2, R3, R4, R9, R 10 , R 11 and R 12 are independently selected from a hydrogen atom, a C1-C12 alkyl, and a C1-C12 alkoxy; R5 and R8 are independently R a and -arylene-R a Selected from (R a is a carboxylic acid group, a carboxylate group, a carbamate group, an unsubstituted or substituted amino group, or a halogen atom), R6, R7, R 13 and R 14 is a hydrogen atom. Represented by formula (1), R1, R2, R3, R4, R9, R 10 , R 11 and R 14 are independently selected from a hydrogen atom, a C1-C12 alkyl, and a C1-C12 alkoxy; R5 and R8 are independently R a and -arylene-R a Selected from (Ra is a carboxylic acid group, a carboxylate group, or a carbamate group), R6, R7, R 13 and R 14 is a hydrogen atom is more preferred.

[0038] Also, represented by formula (1), R2 and R 11 each of R5 and R8 is an anchor group or a linking group substituted with an anchor group; 10 , R 12 , R 13 and R 14 Also preferred are compounds in which each is a hydrogen atom. For example, in the case of the compound represented by formula (1), R2 and R 11 are independently selected from C1-C12 alkyl and C1-C12 alkoxy; R5 and R8 are independently selected from R a and -arylene-R a Selected from (R a is a carboxylic acid group, a carboxylate group, a carbamate group, an unsubstituted or substituted amino group, or a halogen atom), R1, R3, R4, R6, R7, R9, R 10 , R 12 , R 13 and R 14 is a hydrogen atom. Represented by formula (1), R2 and R 11 are independently selected from C1-C12 alkyl and C1-C12 alkoxy; R5 and R8 are independently selected from R a and -arylene-R a Selected from (R a is a carboxylic acid group, a carboxylate group, or a carbamate group), R1, R3, R4, R6, R7, R9, R 10 , R 12 , R 13 and R 14 is a hydrogen atom is more preferred.

[0039] (absorption edge) The optical absorption edge of the polycyclic aromatic hydrocarbon compound of the present disclosure may be 700 nm or less. The polycyclic aromatic hydrocarbon compound of the present disclosure preferably has an absorption edge of 350 to 550 nm, more preferably 400 to 500 nm. By controlling the absorption edge within this range, optical absorption loss by the compound can be suppressed, and high photoelectric conversion efficiency can be expected for the hole-selective contact material of the present disclosure. The absorption edge can be controlled, for example, by changing the number of aromatic hydrocarbon rings or substituents contained in the compound. Because the hole-selective contact layer in a PSC is usually very thin, the upper limit of the absorption edge of the polycyclic aromatic hydrocarbon compound can be set to 550 nm.

[0040] (Solubility) The specific polycyclic aromatic hydrocarbon compounds according to the present disclosure tend to have excellent solubility in solvents. Therefore, the specific hole-selective contact materials according to the present disclosure can be used in wet processes such as spin coating, screen printing, and dipping, making them suitable for the fabrication of photovoltaic devices. The solubility can be controlled, for example, by changing the number of aromatic hydrocarbon rings or substituents contained in the compound.

[0041] (Hole-selective contact material) The hole-selective contact materials according to the present disclosure preferably extract holes quickly and uniformly when used in photovoltaic devices including PSCs, and in particular, the hole-selective contact materials according to the present disclosure preferably stabilize the organic components at the buried perovskite interface when used in PSCs.

[0042] (Photoelectric conversion device) The hole-selective contact materials of the present disclosure can be used in a variety of photovoltaic devices, including photosensors, photodiodes, and solar cells, such as PSCs.

[0043] An example of a PSC is an inverted PSC as shown in Figure 6(a). Typically, an inverted PSC has a substrate (glass in Figure 6(a)), a transparent electrode (ITO in Figure 6(a)), a hole-selective contact layer, a perovskite layer (light-absorbing layer), an electron-selective contact layer, and a back electrode (metal electrode in Figure 6(a)), in this order. In addition to the above, an inverted PSC may also include any known functional layer. The hole-selective contact material according to the present disclosure is suitable for forming the hole-selective contact layer.

[0044] The method for producing a PSC using the hole-selective contact material according to the present disclosure is not particularly limited. For example, the following method can be used.

[0045] The hole-selective contact material according to the present disclosure may be provided in the form of a solution in which a specific polycyclic aromatic hydrocarbon compound is dispersed or dissolved in a solvent. This solution may be applied to the surface of a transparent electrode and dried to form a hole-selective contact layer. The application method is not particularly limited, and examples include spin coating, screen printing, and dipping.

[0046] A perovskite layer may be formed on the hole selective layer by a known method. The material used to form the perovskite layer is not particularly limited, and preferably contains at least one perovskite compound represented by the formula ABX3.

[0047] An electron-selective contact layer may be formed on the perovskite layer by a known method. The material for forming the electron-selective contact layer is not particularly limited, and semiconductor materials such as silicon, germanium, and metal chalcogenides can be used.

[0048] A rear electrode may be formed on the electron selective layer by a known method. The material for forming the rear electrode is not particularly limited, and conductive materials such as metals, carbon compounds, conductive metal oxides, and conductive polymers can be used.

[0049] An optional functional layer includes a compact layer for improving photoelectric conversion efficiency, which can be provided between the transparent electrode and the hole selective contact layer or between the back electrode and the electron selective contact layer. The material for forming the compact layer is not particularly limited, and may be TiO2, TiO x Metal oxides such as SnO2, ZnO2, etc. can be used. The compact layer can be formed using known methods such as sputtering and ALD (Atomic Layer Deposition).

[0050] The hole-selective contact materials according to the present disclosure can be used to form hole-selective contact layers in planar or mesoporous PSCs. [Example]

[0051] The present disclosure will be described more specifically below based on examples.

[0052] The materials and analytical methods used in the experiment are as follows.

[0053] Example 1 (Synthesis and Characterization)

[0054] (material) PbI2 (99.99%, TCI), MAI (GreatCell Solar), MACl (GreatCell Solar), FAI (GreatCell Solar), [6,6]-phenyl-C61-butyric acid methyl ester (PCBM, TCI), fullerene C 60(TCI), bathocuproine (BCP, TCI), MeO-2PACz (TCI), poly(bis(4-phenyl)(2,4,6-trimethylphenyl)amine) (PTAA, TCI), (4-(methoxycarbonyl)phenyl)boronic acid (TCI), tris(dibenzylideneacetone)dipalladium(0) (Pd2(dba)3) (Sigma-Aldrich), 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (SPhos) (Sigma-Aldrich). All chemicals, including ethyl acetate (99.9%, Sigma-Aldrich), K3PO4 (Sigma-Aldrich), MgSO4 (Wako), toluene (Wako), ethyl acetate (99.9%, Sigma-Aldrich, EtOAc, Wako), chlorobenzene (99.8%, Wako), ethanol (Wako), isopropanol (Wako), N,N-dimethylformamide (DMF, Wako), dimethyl sulfoxide (DMSO, Wako), hexane (Wako), and CHCl2 (Wako), were used without further purification.

[0055] (Sample Characterization) Liquid-state nuclear magnetic resonance (NMR) spectra were recorded using a Bruker DPX 400 NMR spectrometer in CD2Cl2 and CDCl3. Chemical shifts (δ) are plotted against the solvent (CD2Cl2, 1 H: 5.32 ppm, 13 Coupling constants (J) were reported in Hertz. Abbreviations: s = singlet, d = doublet, t = triplet. High-resolution mass spectra (HRMS) were recorded on a Thermo Scientific LTQ-Orbitrap electrospray ionization (ESI) mass spectrometer. XPS and UPS spectra were recorded on a Kratos X-ray photoelectron spectrometer (AXIS Ultra HAS) using a monochromated Al Kα (1486.6 eV) source and an inelastic He lα (21.22 eV) source, respectively. After removing the inelastic scattering process, the XPS curves were fitted with a Gauss-Lorentzian function. Scanning Kelvin Probe Microscope (SKPM) measurements show a nominal spring constant of 2.8 N m -1This was performed using an atomic force microscope (AFM, Asylum Research MFP-3D, Oxford Instruments) with a Ti / Ir-coated Si cantilever (model number: ASYELEC-01-R2). The potential difference between the AFM tip and the sample surface was measured using Nap mode with a DC bias voltage applied. Conductive AFM measurements were performed with a force constant of 0.2 N m -1 The measurements were performed using a Cr / Pt coated Si cantilever (Budget Sensors) with the same AFM instrument (contact mode). SEM observations were performed using a Helios NanoLab G3 field emission scanning electron microscope. Low energy inverse photoemission spectroscopy (LEIPS, ALS Technology Co., Ltd.) measurements were performed at a pressure of 10 -10 The experiment was carried out in a high-vacuum chamber at 1000 Torr. A custom-made vacuum suitcase (Ferrovac GmbH) was used for sample transportation to prevent exposure to the environment during the transportation process. X-ray diffraction measurements were performed using a Bruker D8 Discover diffractometer (Bruker AXS) with a Cu (λ = 1.54 Å) source at a power of 1600 W. PL mapping profiles of large-area perovskite thin films were obtained using a Nanofinder® 30 system with an excitation wavelength of 480 nm. TAS measurements were performed using a homemade pump-probe system configured with a CMOS detector (S12198-1024Q, Hamamatsu Photonics) and an InGaAs photodiode array (G9203-256DA, Hamamatsu Photonics). A Yb:KGW laser (Light conversion, Pharos, 1030 nm, 1 kHz repetition rate, 150 fs, 2 mJ per pulse) was used as the primary light source. The output from the laser was split into pump and probe beams. The pump beam was guided through an optical parametric amplifier (Light conversion, ORPHEUS) to generate 343 nm excitation light, and the probe beam was focused onto a YAG plate to generate white continuous light. The mobility was measured using a 663VA Stand (Metrohm) system and a PGSTAT128N (Metrohm) with a JV of ITO / hole selective contact (film thickness 40 nm) / Hg. 2 The plot was measured. To achieve a better hole injection process, a liquid Hg electrode was used, which forms a soft contact at the metal / organic molecular interface. The mobility was calculated using the Mott-Gurney equation μh=8JL 3 / 9ε0ε r V 2 where L is the thickness of the hole selective layer, ε is the vacuum dielectric constant, and ε r is the relative permittivity.

[0056] (In situ MS characterization) In situ MS measurements were carried out in a homemade vacuum chamber combined with a solar simulator and a temperature tracking system. A turbomolecular pump (TMP; HiCube80, Pfeiffer) was used to purify the vacuum chamber (CC-10, VISTA Corporation) to a background pressure of 10. -8The chamber was set to a pressure of Torr. Simulated sunlight was irradiated through a quartz window using a 150W Xe lamp from a solar simulator (PEC-L01, Peccel Technologies, Inc.) installed above the chamber. A perovskite sample deposited on a 5cm x 5cm substrate was fixed in place using a homemade sample holder. A quadrupole mass spectrometer (HAL3F501RC, Hiden Analytical Co., Ltd.) with an m / z range of 1–510 amu and an electron multiplier (to improve signal detection) were installed between the sample holder and the TMP. A thermocouple (RX-450K, AS ONE Corporation) was inserted into the vacuum chamber using an electrical feedthrough and directly connected to the back (glass) surface of the sample, allowing real-time temperature monitoring during MS measurements.

[0057] (Measurement of operational stability) To measure long-term operational stability, the devices were placed in a homemade enclosure box under a dry nitrogen flow, maintaining the relative humidity below 5% and allowing temperature control. A solar simulator (Peccel PEC-L01) was used to continuously irradiate both the small cells and the solar module. A Keithley 2401 source meter, controlled by a customized LabView program, was used to automatically track the output power over time. To simulate the device's operating conditions, a fixed bias voltage close to the initial maximum power point (MPPT) voltage was applied to the device throughout the operation process. The output power was recorded at regular time intervals by the LabView program in response to the fixed bias and photocurrent output.

[0058] (Theoretical calculation) Based on density functional theory (DFT) calculations, the molecular geometries of MeO-2PACz, BPP, and SA-BPP in the gas phase were optimized using the Gaussian 09 program with B3LYP and the all-electron double-ξ valence basis set of 6-31G*. To calculate the absorption energies, In2O3(100) slabs were constructed with MeO-2PACz, BPP, and SA-BPP molecules adsorbed. The lattice relaxation process was carried out within the framework of the DFT method implemented in the Vienna Ab Initio Simulation Package (VASP). A vacuum space of approximately 20 Å was introduced above the model to reduce the interaction between neighboring slabs. The Perdew-Burke-Ernzerhof generalized gradient approximation was used for the exchange-correlation function. Furthermore, to calculate the projected density of the state FAPbI3(100), a three-layer [PbI6] was used. 4- A slab with a unit and a 20Å vacuum space was constructed on top, and [PbI6] 4- The bottom two layers of the unit were fixed during the shape optimization process. The optimized BPP and SA-BPP molecules were added to the surface of FAPbI3, and Pb 2+ The passivation effect of the surface in the state where cations are coordinated was simulated.

[0059] (Synthesis: BPP-Br and SA-BPP) [ka] [ka] Dimethyl 4,4'-(2,11-di-tert-butylbenzo[rst]pentaphen-5,8-diyl)dibenzoate

[0060] As shown in Scheme 1, BPP-Br (A6) and SA-BPP were synthesized. Scheme 1 [ka] THF: tetrahydrofuran, NBS: N-bromosuccinimide

[0061] All reactions involving air- and moisture-sensitive compounds were carried out under an argon atmosphere using standard Schlenk line techniques. Thin-layer chromatography (TLC) was performed on silica gel-coated aluminum sheets using F254 indicator, and column chromatographic separations were performed using silica gel (particle size 0.063–0.200 mm).

[0062] As shown in Figure S1, BPP and BPP-Br (A6) were synthesized. Briefly, 2-bromo-4-(tert-butyl)-1-iodobenzene (A2) was prepared by the Sandmeyer reaction of 2-bromo-4-(tert-butyl)aniline (A1), followed by selective halogen-metal exchange to generate the corresponding Grignard reagent, which was then reacted with DMF to give the aldehyde (A3). Suzuki-Miyaura coupling of aldehyde (A3) with diboronic ester (A4) gave dialdehyde (A5), which underwent a "dehydrative π-extension" (DPEX) reaction to give di-tert-butyl-benzo[rst]pentaphene (BPP). Next, BPP was brominated with N-bromosuccinimide (NBS) to give BPP-Br (A6).

[0063] Finally, the Suzuki-Miyaura coupling of BPP-Br (A6) and 4-(methoxycarbonyl)phenylboronic acid gave SA-BPP in 76% yield. The chemical structure of SA-BPP was confirmed by nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (HRMS). To synthesize dimethyl 4,4'-(2,11-di-tert-butylbenzo[rst]pentaphene-5,8-diyl)dibenzoate (SA-BPP), 5,8-dibromo-2,11-di-tert-butylbenzo[rst]pentaphene (BPP-Br(A6)) (50.0 mg, 0.0877 mmol), 4-(methoxycarbonyl)phenylboronic acid (66.0 mg, 0.263 mmol), and 2,11-di-tert-butylbenzo[rst]pentaphene (BPP-Br(A6)) (50.0 mg, 0.0877 mmol) were used. ol), tris(dibenzylideneacetone)dipalladium(0) (Pd2(dba)3) (4.00 mg, 4.38 μmol), 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (SPhos) (3.60 mg, 8.77 μmol), K3PO4 (118 mg, 0.556 mmol), and anhydrous toluene (2 mL) were placed in a 100 mL Schlenk tube under an argon atmosphere. The reaction mixture was subjected to freeze-pump-thaw cycles (three times) and heated at 105 °C for 20 h under an argon atmosphere. The resulting mixture was cooled to room temperature and poured into water (20 mL). The organic layer was separated, and the aqueous layer was extracted three times with CHCl2 (10 mL). The separated organic phases were combined, washed with brine, dried over anhydrous MgSO4, and evaporated. The residue was purified by silica gel column chromatography (eluent: hexane: EtOAc = 10:1) to give SA-BPP as a pale yellow solid (45.5 mg, yield 76%).

[0064] 1 H NMR(400MHz,CD2Cl2)δ9.41(s,2H),9.16(d,J=1.9Hz,2H),8.30-8.16(m,4H),7.77(dd,J=8.8,1. 8Hz, 2H), 7.70 (dd, J=8.8, 0.5Hz, 2H), 7.60-7.51 (m, 4H), 7.27 (s, 2H), 3.98 (s, 6H), 1.58 (s, 18H). C NMR (101 MHz, CDCl) δ 166.85, 149.26, 144.24, 134.19, 131.49, 129.58, 128.71, 128.20, 126.97, 126.79, 126.14, 125.37, 124.49, 122.14, 118.42, 52.08, 35.33, 31.21. HRMS (ESI, positive): 682.3078 [M] + ,Detected:682.3093.

[0065] Figure 1 shows a) BPP using CD2Cl2 1 H NMR spectrum (400 MHz, 298 K), and b) 13 C NMR spectrum (101 MHz, 298 K) is shown. Figure 2 shows a) the activity of SA-BPP with CD2Cl2 1 H NMR spectrum (400 MHz, 298 K), and b) 13 C NMR spectrum (101 MHz, 298 K) is shown. Figure 3 shows the high-resolution mass spectra of a) BPP and b) SA-BPP (top: calculated isotope distribution pattern, bottom: experimental isotope distribution pattern).

[0066] As shown in Figure 2, neither BPP nor SA-BPP had detectable impurity peaks in their NMR spectra, indicating the high purity of the compounds. In particular, SA-BPP powder can be easily dissolved in commonly used green solvents such as ethyl acetate, enabling the open-air fabrication of SA-BPP hole-selective contacts for solar cell module fabrication.

[0067] (Synthesis: BPP-MeOPA) [ka]

[0068] BPP-MeOPa was synthesized according to the method described in the following references. X. Xu et al., “Solvent-tunable exciton-charge transfer mixed state enhances emission of functionalized benzo[rst]pentaphene through symmetry breaking”, Chemical Communications, 2023, 2023,59, 720-723

[0069] (Synthesis: BPP-Boc) [ka]

[0070] BPP-BOC was synthesized as shown in Scheme 2. Scheme 2 [ka]

[0071] Figure 4 shows the cleavage of BPP-Boc using CD2Cl2. 1 The H NMR spectrum (400 MHz, 298 K) is shown.

[0072] (Density Functional Theory (DFT) calculations) Density functional theory (DFT) calculations revealed the distribution of the frontier molecular orbitals of BPP and SA-BPP. As can be seen in Figure 5, both the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) are overlying the fused six-membered benzenoid ring of BPP, resulting in a strong delocalization of the electron cloud. In the case of SA-BPP, both the HOMO and LUMO extend partially to the electron-withdrawing benzoic acid end groups. This delocalized frontier orbital distribution significantly improves the photostability of the organic semiconductor.

[0073] (Characteristics of BPP and SA-BPP) Figure 6a shows the chemical structures of the BPP and SA-BPP molecules, as well as a schematic diagram of the SA-BPP hole-selective contact that can form bonds with both the ITO substrate and the perovskite layer in an inverted PSC.

[0074] To clarify the band structure of these graphene-like molecules, we performed ultraviolet photoemission spectroscopy (UPS) and low-energy inverse photoemission spectroscopy (LEIPS) to measure the positions of the HOMO and LUMO relative to the Fermi level (EF). As shown in Figure 6c, the energy gap between the HOMO and LUMO was calculated to be 2.84 eV for BPP and 2.78 eV for SA-BPP, indicating that the SA-BPP molecule exhibits more p-type properties.

[0075] The ionization potentials, calculated from the secondary electron cutoff features of the UPS spectra, were 5.05 eV for BPP and 5.24 eV for SA-BPP, suggesting energy offsets of 0.41 eV and 0.22 eV relative to the valence band maximum (VBM) of the perovskite thin film (in this study, cesium-formamidinium-methylammonium-lead iodide (CsFAMAPbI3)). Such a deep HOMO level in SA-BPP is attributed to the reduced electron density in the BPP core due to the electron-withdrawing benzoic acid end groups. Furthermore, the deeper EF position of SA-BPP compared to BPP and pure ITO allows for a barrier-free hole extraction process from the perovskite absorber to the hole contact (Figure 6d).

[0076] Next, Fourier transform infrared spectroscopy (FTIR) was used to characterize the interaction of SA-BPP molecules with ITO or perovskite components. As shown in Figure 6b, the pure SA-BPP sample exhibited a peak at 1726 cm -1 (C=O stretching vibration), 1605cm -1 (C=C stretching vibration), 1438cm -1 (CH bending vibration), 1282 cm -1 (C-C stretching vibration), and 1099 cm -1 The IR absorption characteristic of SA-BPP is the bending vibration of the Pb-H (C-H bond on the phenyl ring). After mixing with ITO or PbI2 powder, the vibration peak intensity of the C=O group was significantly reduced compared to the C=C (C-C) and C-H vibration peaks of SA-BPP. This indicates a deformation of the electron cloud of the C=O group due to the formation of a C=O····Pb bond with PbI2 or a C=O····(Sn, In) bond with ITO.

[0077] (Self-anchoring behavior of BPP and SA-BPP) The self-anchoring behavior of BPP and SA-BPP molecules on an In2O3(100) surface (simulating ITO) was investigated using DFT methods. MeO-2PACz, which is often used to fabricate high-performance inverted PSCs, was selected as a reference sample. In the In2O3(100) / MeO-2PACz sample, strong electron cloud binding was observed between the phosphonic acid groups and the surface In atoms, resulting in a calculated adsorption energy (Eads) of -2.15 eV. However, due to the lack of anchoring groups, BPP molecules exhibited a very low Eads of -0.34 eV on the In2O3(100) surface. In contrast, the SA-BPP molecule / In2O3(100) interface exhibited two distinct charge redistribution sites due to bonds formed between the C=O groups and the In2O3 surface In atoms, resulting in a much higher Eads of -2.61 eV.

[0078] These different anchoring behaviors were characterized using XPS. XPS C 1s spectra were measured for MeO-2PACz, BPP, and SA-BPP films deposited on ITO glass before and after solvent washing. The C 1s peak intensity of the MeO-2PACz film decreased to 88% of its initial value after washing with isopropanol (IPA) and to 76% after washing with N,N-dimethylformamide (DMF), indicating the removal of unbound extraneous molecules from the surface. For the BPP film, the C 1s peak intensity decreased to less than 30% of its initial value after washing with DMF. This indicates that the BPP layer can be easily removed after the solution-based perovskite layer deposition. In contrast, the SA-BPP film retained more than 80% of its initial peak intensity even after washing with DMF, confirming the strong bonding strength of SA-BPP on the ITO substrate.

[0079] To visualize the uniformity of the hole-selective thin films coated on ITO glass, we used a surface-sensitive technique, scanning Kelvin probe microscopy (SKPM), to obtain surface potential mapping profiles of 50 μm × 50 μm areas of various hole-selective contacts. As shown in Figures 7a–c, the BPP film exhibits bright green (low potential) and red (high potential) regions in the mapping profiles. However, the SA-BPP film exhibits a smaller difference between the minimum and maximum potential values ​​than the BPP and MeO-2PACz films, resulting in a more uniform color mapping. A possible reason for this is the more ordered loading of the ITO surface due to the anchoring effect of the two sites of the SA-BPP molecules. In contrast, the nonuniform potential distribution of the BPP film is likely due to intermolecular aggregation caused by strong π-π interactions.

[0080] Scanning electron microscopy (SEM) measurements were performed to investigate the morphology of the perovskite thin films deposited on various hole-selective contacts. As shown in Figure 7d–f, the perovskite thin films deposited on MeO-2PACz and SA-BPP had smoother surface morphologies compared to the perovskite thin film grown on BPP.

[0081] Furthermore, the surface potential mapping profile (50 μm × 50 μm) of the perovskite thin film deposited on SA-BPP showed much smaller potential fluctuations than those of the perovskite thin films deposited on BPP and MeO-2PACz (Figure 8). On the other hand, cross-sectional SEM images (Figures 7g-i) show that the ITO / MeO-2PACz / perovskite and ITO / SA-BPP / perovskite samples have no pinholes at the contacts, whereas the BPP / perovskite interface has many pinholes due to the random orientation of perovskite grains, which usually cause non-radiative recombination of carriers.

[0082] Next, the crystalline structure of the perovskite thin films was evaluated by X-ray diffraction (XRD) measurements. Figure 9 shows the XRD patterns of different samples. The perovskite thin films on the BPP substrate exhibited smaller peak intensities of the (100) and (200) crystal planes, which are important for charge carrier transport within the perovskite absorber, compared to the XRD patterns of the SA-BPP / perovskite or MeO-2PACz / perovskite samples. These results suggest that the strong chemical bond between the hole-selective contact and the buried perovskite interface is important for the growth of compact, highly oriented perovskite crystals.

[0083] Example 2 (Interfacial Charge Carrier Dynamics)

[0084] (TAS measurement) Interfacial carrier dynamics was investigated by femtosecond transient absorption spectroscopy (TAS), using a sample structure of glass / hole-selective contact / perovskite layer.

[0085] As shown in Figure 10a–c, a specific ground-state bleaching (GSB) peak was formed around 749 nm in CsFAMAPbI3 perovskite, and the GSB peak decay process was detected with pump-probe delay times ranging from 30 ps to 500 ps. The decay rate of the GSB peak signal indicates the efficiency of carrier transport from the perovskite absorber to the hole contact. A significant decay of over 95% of the GSB peak intensity was observed in the SA-BPP / perovskite film between delay times of 30 ps and 500 ps compared with the MeO-2PACz / perovskite film (81%) and the BPP / perovskite film (64%), indicating a high hole extraction efficiency at the SA-BPP / perovskite interface. Next, the decay lifetimes of the GSB peaks were calculated by fitting the decay kinetics plots of the TAS spectra. These were 103.2 ps for MeO-2PACz / perovskite, 146.5 ps for BPP / perovskite, and 80.1 ps for SA-BPP / perovskite (Figure 11).

[0086] (PL mapping) Furthermore, we investigated the uniformity of the charge extraction process at the hole contact interface using photoluminescence (PL) mapping techniques. Figures 10d–f show the PL mapping profiles of the corresponding samples in a 100 μm × 100 μm area. The blue area indicates a strong PL quenching effect, while the red area indicates a weak PL quenching effect. The PL mapping intensity was inhomogeneous for the MeO-2PACz / perovskite and BPP / perovskite samples, indicating a large variation in charge extraction behavior. This variation in PL characteristics over the microscale region is attributed to the inhomogeneity of the perovskite morphology and the quality of the hole contact. In contrast, the PL mapping profile of the SA-BPP / perovskite exhibited a more uniform hole extraction process, which is relevant and important for achieving efficient charge carrier separation in large-area devices.

[0087] (Other measurements) In general, the charge extraction process is strongly affected by carriers (μh). Dark current density - voltage 2 (JV 2 The hole mobility (μh) of various hole-selective contacts was estimated by calculating the slope of the JV plot according to the Mott-Gurney equation. 2 The plot was measured using hole-only devices containing MeO-2PACz or SA-BPP layers. The μh of SA-BPP was (4.27±0.29)×10 -4 cm 2 V -1 s -1 The calculated value was MeO-2PACz (μh = (7.12 ± 0.15) × 10 -5 cm 2 V -1 s -1 is six times larger than

[0088] In addition to the mobility, the trap density (Ntrap) at the buried perovskite interface is also considered to be an important factor in determining the hole extraction efficiency. In this study, the value of Ntrap was measured by the space charge limited current (SCLC) method. The Ntrap value was 7.95 × 10 for the MeO-2PACz-based sample. 15 cm -3 , and 9.93 × 10 for the BPP-based sample. 15 cm -3 , and 6.34 × 10 for the SA-BPP sample. 15 cm -3 It is estimated that SA-BPP can minimize trap states, thereby enabling fast extraction of photogenerated holes in perovskite absorbers.

[0089] We clarified the passivation mechanism of SA-BPP contacts by simulating the interaction of SA-BPP or BPP molecules with iodide vacancies, which are considered to be the main defect source in iodide-based perovskite materials. Here, we adopted a pure cubic FAPbI3 perovskite model to simplify the calculation process. Figure 12 shows the density of states (DOS) distributions for FAPbI3(100) slabs without passivation and with SA-BPP or BPP passivation. The inset shows the corresponding geometry-optimized structures with iodide vacancies (indicated by blue circles) on the surface. In pure FAPbI3 slabs, the charge distribution of the HOMO orbital is localized, which generates additional trap states at both the valence and conduction band edges, leading to electron-hole recombination. These calculation results are consistent with previous analyses of defect-containing perovskite structures. In the case of the BPP-passivated FAPbI3 slab, trap states also exist at the band edges due to the weak electronic coupling between the BPP core and undercoordinated Pb cations on the surface. In contrast, the chemical bonding between the C=O groups of SA-BPP and the undercoordinated Pb cations on the surface effectively delocalizes the charge distribution around the Pb-I framework, minimizing the trap densities at the valence and conduction band edges in the SA-BPP-passivated FAPbI3 model.

[0090] Example 3 (Stability and Relative Interface of Hole-Selective Contacts) For systematic comparison, we further investigated the stability of the SA-BPP hole-selective contact under continuous 1-sun irradiation. The commonly used carbazole-based MeO-2PACz and triphenylamine-based PTAA were used as reference samples. The changes in the XPS C 1s core levels before and after aging are shown in Figure 13a. Among the isolated peaks, the peak at 284.5 eV is associated with the C-C (C=C) bond of MeO-2PACz, the peak at 285.3 eV is associated with the C-N bond, the peak at 286.2 eV is associated with the C-O-C bond, and the peak at 287.3 eV is associated with the C-P bond. After 100 h of 1-sun irradiation, the C-N and C-P peak intensities significantly decreased, indicating the degradation of the carbazole core and the phosphonate anchoring group. In contrast, the SA-BPP sample (Figure 13b) showed no obvious changes in the C-C, C-O, and O=CO peak intensities. This suggests that the BPP core and benzoic acid end groups remained stable even after aging under the same conditions. Furthermore, in the PTAA contact, photodegradation of the triphenylamine unit was significant, with the peak intensity of the C–N bond decreasing by approximately 30% after aging (Figure 13c).

[0091] Furthermore, we performed conductive atomic force microscopy (C-AFM) measurements to investigate the effect of structural changes on the conductivity of these hole-selective contacts. As shown in Figure 14, the C-AFM current mapping profile of the MeO-2PACz film showed a significant decrease in average current from 1.68 nA to 0.81 nA after 100 h of aging with 1-sun irradiation under the same applied bias. The mapping current of the PTAA film showed a similar decrease (1.62 nA to 1.19 nA). In contrast, the SA-BPP film showed only a small change in mapping current (0.17 nA) after aging. These results strongly demonstrate the superior photostability of SA-BPP compared to the benchmarks MeO-2PACz and PTAA.

[0092] In addition to the hole-selective contact itself, the relative perovskite buried interface also plays an important role in the long-term operational stability of inverted PSCs. In situ mass spectrometry (MS) techniques are powerful tools for stability studies, allowing us to identify gas-phase decomposition products and investigate the evolution of their partial pressures under the influence of light and heat. We have used this technique in previous studies to clarify the mechanisms of temperature- or light-dependent degradation of perovskite materials and relative interfaces. Here, we used an MS system to investigate the effects of background pressures of 10 -8 Decomposition products released from the hole-selective contact / perovskite interface under simulated 1-sun irradiation were tracked in a Torr vacuum chamber. A schematic diagram of this in-situ MS system is shown in Figure 15a. Figures 13d-f show MS contour plots of the mass-to-charge ratios (m / z) of 1–200 amu for perovskite thin films deposited on MeO-2PACz, SA-BPP, and PTAA substrates, respectively. The degradation pathways derived from these MS plots are summarized in Figure 13g. After exposure to 1-sun light, decomposition products with m / z values ​​of 17 amu, 27 amu, 31 amu, 44 amu, 73 amu, 127 / 128 amu, and 142 amu were detected, corresponding to NH3 + , H.C.N. + , CH3NH2 + (MA gas), CH(N2H3) + (FA gas), DMF + (N,N-dimethylformamide solvent), I + / HI + (hydrogen iodide), and CH3I + (methyl iodide). Also, CH3 + (m / z=15, methyl group), NH2 + (m / z=16, amino group), CH4N + (m / z=30, MA fragment), CH2N2 + (m / z=42, FA fragment), I2 +Fragments generated during the ionization process were also detected by mass spectrometry, such as (m / z = 63, iodide fragment). The production of FA, MA, and HI in the gas phase is attributed to the deprotonation reaction of the organic ammonium compounds. The deprotonation process is accelerated under continuous illumination or high temperatures, as indicated by the increase in the partial pressure of the corresponding compounds. NH, HCN, and CHI were also generated by the thermal decomposition of CH(N2H3) and the reaction of CH3NH2 with HI. As shown in Figures 15b-d, after 120 min of irradiation, the partial pressures of NH3, CH3NH2, CH(N2H3), and HI increased 3-4 times in the MeO-2PACz / perovskite sample, while the partial pressures of CH3NH2 and CH(N2H3) increased by approximately one order of magnitude in the PTAA / perovskite sample. In contrast, fewer decomposition products were released from the SA-BPP / perovskite sample. In other words, the deprotonation and decomposition of organic components in the perovskite absorber are effectively suppressed under operating conditions, which is attributed to the good quality of the perovskite crystals and the improved interfacial stability provided by the SA-BPP contact.

[0093] To further demonstrate the possible reasons for the enhanced stability at the buried perovskite interface, the electrostatic potential (ESP) profiles of MeO-2PACz, SA-BPP, and PTAA were calculated based on DFT methods (Figure 16a). In the MeO-2PACz and PTAA models, negative ESP (shown in red) is mainly present in the electron-rich benzene rings of the carbazole and triphenylamine units, while a much higher electron density is observed in the BPP core of SA-BPP. The high electron density in the BPP core can be attributed to the strong delocalization effect of π electrons, which is likely due to the FA. + or MA + The SA-BPP molecule and the FA molecule can provide active sites for forming cation-π interactions with cations. + The interaction energy between the cation and the cation was calculated to be −1.08 eV, which is the same as that of MeO-2PACz-FA. + Complex (-0.47 eV) or PTAA-FA +This is much larger than that of the complex (-0.28 eV). Such cation-π interactions fix volatile organic cations at the buried perovskite interface, thereby suppressing photodegradation of perovskite crystals under operating conditions.

[0094] Example 4 (Device Performance and Stability)

[0095] (Fabrication of small PSCs) ITO glass substrates were washed sequentially with distilled water, isopropanol, and acetone. After drying the substrates under a stream of N2, they were treated with ultraviolet (UV) / O3 for 40 minutes. Next, a 0.003 M precursor solution (ethyl alcohol for MeO-2PACz, ethyl acetate for SA-BPP, and chlorobenzene for BPP) was spin-coated at 3000 rpm for 30 seconds and annealed at 100 °C for 15 minutes to form a hole-selective layer on the ITO substrate. For the deposition of the PTAA layer on the ITO substrate, 1 mg mL -1 A PTAA toluene solution was spin-coated onto the substrate at 5000 rpm for 30 seconds, followed by annealing at 120 °C for 20 minutes. Next, a solution of 1.35 M PbI2 and 0.0675 M CsI in DMF / DMSO (19:1, v / v) was spin-coated at 3000 rpm for 30 seconds in a N2 glove box. Next, following our previous work, a mixed organic cation solution (60 mg FAI, 20 mg MAI, and 5 mg MACl dissolved in 1 ml isopropanol) was spin-coated at 3000 rpm for 30 seconds, followed by annealing at 150 °C for 10 minutes in air, resulting in triple-cation CsI. 0.05 (FA 0.78 MA 0.22 ) 0.95 The PbI3 perovskite layer was then formed. Next, 5 mg mL -1 The PCBM chlorobenzene solution was spin-coated onto the perovskite surface at 1000 rpm for 30 seconds and annealed at 70 °C for 10 minutes. -7 C under vacuum conditions of Torr 60 20 nm of ZnO, 5 nm of BCP, and 80 nm of Ag electrode were evaporated onto the substrate in this order. Miniature PSCs using BPP-Br, BPP-MeOPA, and BPP-Boc were prepared in the same manner as above.

[0096] (Fabrication of perovskite solar cell modules) The perovskite solar cell module consists of seven perovskite subcells connected in series on a 5cm x 5cm ITO substrate. The P1 pattern on the ITO substrate was designed by Yingkou OPV Tech New Energy. The ITO substrate with the P1 pattern was cleaned, and a hole-selective layer was formed using the spin-coating method described above. The perovskite layer was spin-coated on the 5cm x 5cm substrate using the same sequential deposition method as for the small PSC, followed by a two-step annealing process: annealing at 90°C for 1 minute and then at 150°C for 10 minutes. The PCBM layer and C 60 After the layer was deposited, the sample was etched using a picosecond laser (Picosecond Laser Processing System, LPS-R002A, Spectronics Corporation) at a laser wavelength of 532 nm (output power of 3.0 W) with a pulse time of 12 ps to form the P2 pattern. Next, an atomic layer deposition (ALD, Cambridge Nanotechnology, Savannah S200) was used to form the P2 pattern at low temperature. 60 A 5-nm compact layer of tin oxide was deposited on the surface. Tetrakis(dimethylamino)tin(IV) (TDMASn) was selected as the tin source, and the growth rate of the ALD-SnO2 layer was fixed at 0.53 Å per cycle. Next, the sample was transferred to a high-vacuum chamber, and an 80-nm Ag electrode was evaporated on the ALD-SnO2 protective layer. Finally, after Ag deposition, a P3 pattern was formed using a 3.8-W laser.

[0097] (PSC Characterization) Under irradiation with AM1.5G light (100 mW cm -2The J-V curves of the devices were measured at room temperature and 30% relative humidity using a solar simulator (Newport Oriel Sol 1A, xenon lamp, Ushio, UXL-150SO) and a Keithley 2420 source meter without pretreatment, calibrated with a KG3 reference silicon cell (Enlitech). The J-V scan range for the small cell was -0.1 to 1.2 V, and the aperture area was 0.1 cm. 2 A metal mask with an aperture area of ​​22.4 cm was used for the measurement. For a 5 cm x 5 cm solar cell module, the JV scan range was set to -0.1 to 8.5 V. 2 The mask of the following was used for the measurement. The IPCE spectra of the inverted PSCs were characterized using an Oriel IQE 200 system.

[0098] (Photovoltaic performance) ITO / SA-BPP / Perovskite (500~550nm) / PCBM / C 60 Inverted planar PSCs with the structure of SA-BPP / BCP / Ag (Figure 17a) were fabricated to investigate the effect of SA-BPP on the photovoltaic performance. For comprehensive comparison, MeO-2PACz and BPP were used as references. Figure 17b shows the results of the SA-BPP / BCP / Ag PSCs with various hole-selective contacts and an aperture area of ​​0.1 cm. 2 The photovoltaic parameters of the champion devices are shown in Table 1. For the MeO-2PACz device, the maximum PCE was 20.57% (reverse scan), with an open circuit voltage (V) of 1.15 V and a short circuit current density (J) of 22.11 mA cm. -2 The fill factor (FF) was 80.89%. In contrast, the SA-BPP device exhibited an obvious improvement in photovoltaic performance, with a maximum PCE of 22.03%, VOC of 1.17 V, and JSC of 22.55 mA cm. -2 The FF was 83.50%. On the other hand, the BPP device had a relatively low PCE of 14.51%, a VOC of 1.06 V, and a JSC of 20.65 mA cm. -2, and FF was 66.31%. In this regard, we attribute the improved efficiency in the SA-BPP device to the rapid hole extraction process, efficient passivation of the buried perovskite interface, and the high mobility of the large conjugated SA-BPP molecules. Furthermore, the reproducibility of the SA-BPP device is higher than that of the reference sample, given the narrow statistical distribution of the photovoltaic parameters.

[0099] (External quantum efficiency (EQE) spectrum) The external quantum efficiency (EQE) spectra of the corresponding PSCs were investigated, as shown in Figure 17c. The results showed that the incorporation of the SA-BPP hole-selective contact significantly improved the EQE in the short wavelength region between 350 and 480 nm. This EQE improvement is associated with an improved carrier extraction efficiency at the emission side (buried perovskite interface), further supporting the TAS and PL measurements. The integrated JSC obtained from the EQE spectra was 22.08 mA cm for the MeO-2PACz device. -2 , 22.49 mA cm for the SA-BPP device -2 was calculated, which was consistent with the JSC obtained from the JV measurement.

[0100] Maximum photovoltaic performance of small cells and solar modules using various hole-selective contacts [Table 1]

[0101] (Evaluation of solar cell modules) To evaluate the mass production potential of SA-BPP inverted PSCs, we fabricated a 5 cm × 5 cm solar cell module consisting of seven perovskite subcells connected in series (Figure 17d). The deposition methods for the various functional layers were similar to those used in the small-scale cells: SA-BPP contacts (spin coating), perovskite absorber (spin coating), electron-selective contacts (evaporation), and Ag electrodes (evaporation). The solar cell module structure is shown in Figure 17e, and the corresponding pattern design is shown in Figure 18a. Based on the subcell width and the dead area between P1 and P3, the geometric fill factor (GFF) was calculated to be 95.8% (Figure 18b). Furthermore, a conformal, compact layer of tin oxide was deposited on the P2 pattern by atomic layer deposition (ALD). This ALD-SnO2 layer was designed to prevent direct contact between the iodide-based perovskite absorber and the Ag electrode, which could accelerate degradation of the inverted PSC module under light and thermal conditions.

[0102] For the SA-BPP-based solar cell module, the corresponding J-V curve (Fig. 17e) shows that the reverse scan PCE is 0.01 for an aperture area of ​​22.4 cm 2 at 17.08% (active area PCE is 17.83%), VOC is 7.68 V, and JSC is 2.87 mA cm -2 The MeO-2PACz solar cell module had a relatively low PCE of 14.77% (active area PCE of 15.42%), a VOC of 7.48 V, and a JSC of 2.81 mA cm. -2 The FF was 70.28%. We also used a large-area PL mapping method to investigate the uniformity of perovskite thin films deposited on 5 cm × 5 cm substrates. As seen in Figure 17f, the perovskite film coated on the 5 cm × 5 cm ITO / SA-BPP substrate exhibited a more uniform PL mapping intensity than the film coated on the ITO / MeO-2PACz substrate. The bright lines in the mapping profile indicate that the PL quenching effect is relatively weak in the P1 pattern of the ITO glass.

[0103] (operation stability) The operational stability of PSC miniature cells and modules was evaluated under accelerated aging conditions based on the International Summit on Organic Photovoltaic Stability (ISOS) protocol using a homemade test system (Figure 19a) and a xenon white light source (the spectrum of which is shown in Figure 19b) to simulate solar irradiation.

[0104] Figure 20a shows the normalized PCE decay curves for bare PSCs with MeO-2PACz, SA-BPP, and PTAA hole-selective contacts measured at 45 °C (ISOS-L-2I) under 1-sun illumination. The decay plots of the actual PCE values ​​are shown in Figure 21. The continuous operation times at which the normalized PCE decreased by more than 20% were 622 h for the reference MeO-2PACz device and 1,030 h for the PTAA device. In contrast, the SA-BPP device exhibited a linear PCE decay plot, maintaining approximately 87.4% of its initial efficiency even after 2,000 h of operation. This corresponds to a T80 lifetime of 3,175 h, the longest operational lifetime for an inverted PSC.

[0105] [Table 2]

[0106] The stability and reproducibility of the SA-BPP devices were evaluated by tracking the PCE decay profiles of each of the six cells under the same conditions (1-sun irradiation under dry N2 flow). All devices showed a PCE decay of 0.0037% h−1 over 500 h of operation. -1 ~0.0041% time -1 showed a similar PCE decay rate.

[0107] The operational stability of solar cell modules is one of the most important issues for the commercialization of PSCs. In this regard, we tracked the PCE decay versus operating time of a 5 cm × 5 cm inverted PSC module, as shown in Figure 20b (ISOS-L-2I). The SA-BPP-based module maintained 88.5% of its initial efficiency after 1,000 hours of operation and significantly extended its estimated T80 lifetime to 1,739 hours compared to the MeO-2PACz-based module (353 hours).

[0108] To suppress the reaction of the iodide component of the perovskite layer with the Ag electrode due to lateral ion diffusion in the contact area, an ALD-SnO2 compact layer was deposited on the solar cell module (patterns P2 and P3). XPS high-resolution O 1s (Fig. 22a) and Sn 3d (Fig. 22b) spectra showed that the electron-selective contact (PCBM / C 60 ) shows the formation of tin oxide on the surface. Optical microscope images (Figure 22c) show that the application of this ALD protective layer suppresses the corrosion of the Ag electrode under 1-sun irradiation at the edge of P2 and P3.

[0109] (Evaluation of PSC using BPP-Br, BPP-MeOPA, and BPP-Boc) Inverted planar PSCs using BPP-Br, BPP-MeOPA, and BPP-Boc instead of SA-BPP were fabricated in the same manner as above, and their photovoltaic performance and operational stability were evaluated. Figures 23a, 24a, and 25a show the photovoltaic performance of various hole-selective contacts with an aperture area of ​​0.1 cm at 45 °C in an N-filled chamber. 2 23a, 24a, and 25a are plots of the J-V curves of small PSCs with aperture areas of 0.1 cm using various hole-selective contacts. 2 1 is a plot of the JV curve of a small PSC.

Claims

1. a hole-selective contact material comprising a polycyclic aromatic hydrocarbon compound; The polycyclic aromatic hydrocarbon compound has a structure having a plurality of aromatic hydrocarbon rings, each of which is fused with at least one other aromatic hydrocarbon ring, and at least one anchor group is attached to the structure directly or via a linking group, to form a hole-selective contact material.

2. 2. The hole-selective contact material of claim 1, wherein the anchor group is selected from the group consisting of carboxylic acid groups, carboxylate groups, cyanoacrylic acid groups, cyanoacrylate groups, pyridine groups, phosphonic acid groups, tetracyanate groups, perylenedicarboxylic anhydride groups, 2-hydroxybenzonitrile groups, 8-hydroxyquinoline groups, pyridine-N-oxide groups, 3-hydroxy-N-methylpyridinium groups, catechol groups, hydroxamate groups, sulfonic acid groups, acetylacetonate groups, boronic acid groups, nitro groups, tetrazole groups, rhodamine groups, rhodamine-3-acetic acid groups, salicylic acid groups, aldehyde groups, carbamate groups, unsubstituted or substituted amino groups, unsubstituted or substituted ammonium groups, halogen atoms, and imine groups.

3. 10. The hole-selective contact material of claim 1, wherein the linking group is selected from the group consisting of alkylene, alkenylene, alkynylene, cycloalkylene, arylene, and heteroarylene groups.

4. 2. The hole-selective contact material of claim 1, wherein the structure having multiple aromatic hydrocarbon rings has an absorption edge between 350 and 550 nm.

5. 5. The hole-selective contact material of claim 4, wherein the structure having multiple aromatic hydrocarbon rings has an absorption edge between 400 and 500 nm.

6. 2. The hole-selective contact material of claim 1, wherein the plurality of aromatic hydrocarbon rings is from 3 to 16 aromatic hydrocarbon rings.

7. 10. The hole-selective contact material of claim 1, wherein the plurality of aromatic hydrocarbon rings is a plurality of benzene rings.

8. 10. The hole-selective contact material of claim 1, wherein the structure is benzo[rst]pentaphene.

9. 10. The hole-selective contact material of claim 1, wherein the polycyclic aromatic hydrocarbon compound comprises at least one solubility-enhancing group.

10. 10. The hole-selective contact material of claim 9, wherein the solubility-enhancing group is selected from the group consisting of alkyl groups, alkoxy groups, aryl groups, and ester groups.

11. A photovoltaic device comprising the hole-selective contact material according to any one of claims 1 to 10.

12. The photovoltaic device according to claim 11 , wherein the photovoltaic device is a perovskite solar cell.

13. A polycyclic aromatic hydrocarbon compound represented by formula (1): 【Chemistry 1】 In the above formula, R １ , R ２ , R ３ , R ４ , R ９ , R １０ , R １１ and R １２ are independently selected from a hydrogen atom, a C1-C12 alkyl, and a C1-C12 alkoxy; R ５ and R ８ becomes independent and R ａ and -arylene-R ａ is selected from (R ａ is a carboxylic acid group, a carboxylate group, or a carbamate group), R ６ , R ７ , R １３ and R １４ is a hydrogen atom.

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