Aromatic Alkylammonium Spacer Cations for Efficient Two‐Dimensional Perovskite Solar Cells with Enhanced Moisture and Thermal Stability

Abstract

Three‐dimensional (3D) perovskite solar cells are prone to degradation in the presence of moisture, heat, and light. Recently, two‐dimensional (2D) perovskites are synthesized by isolating metal halide perovskite layers using aliphatic or aromatic alkylammonium spacer cation, which can retain their performance under ambient humidity levels due to the hydrophobic property of the spacer cation. However, the best 2D perovskite thus far, using aliphatic short butylammonium (BA) cation as spacer cation, shows only a modest tolerance against moisture and heat due to the inferior hydrophobicity as well as the relatively smaller size of the BA cation. Here, a bulkier aromatic phenylethylammonium (PEA) used as a spacer cation to synthesis 2D perovksite in order to achieve highly stable solar cells. By modifying the crystallization process, an average power conversion efficiency (PCE) of 5.50% is achieved, which is the highest reported PCE for aromatic alkylammonium‐based lower dimensional perovskite solar cells. Importantly, unencapsulated (PEA)2(MA)3Pb4I13 devices show enhanced moisture stability compared to other reported perovskite solar cells in harsh moisture environment (72 ± 2% relative humidity). Moreover, the use of organic materials in p‐i‐n type device, instead of metal oxides, as electron and hole extraction layers also paves the way toward constructing flexible perovskite solar cells.

Tailored PEDOT:PSS hole transport layer for higher performance in perovskite solar cells: Enhancement of electrical and optical properties with improved morphology

“…Metal halide perovskites have emerged as a promising photovoltaic technology due to their solution processibility, low fabrication costs, high power conversion efficiency and rapid energy payback time [1][2][3][4][5][6] . Due to excellent light absorption, devices.…”

Water-resistant 2D lead(ii) iodide perovskites: correlation between optical properties and phase transitions

“…22,[29][30][31] From the commercialization of perovskite-based solar cell technology point of view, there is an urgent need to improve the stability of the perovskites in the near future. In literature, there are very few 2D perovskite materials reported that are stable under humid conditions, 29,32,33 thermal stress [34][35][36] and continuous illumination to UV light. 29 The quest to develop a stable perovskite material that can outperform under ambient conditions has motivated us to investigate the long carbon chain (C 14 , C 16 and C 18 ) organic cations in 2D perovskite.…”

Nanoscale control of grain boundary potential barrier, dopant density and filled trap state density for higher efficiency perovskite solar cells

“…Organolead halide perovskite materials have been used as the active material in a range of optoelectronic device based applications such as light emitting devices, photodetectors etc. However, the understanding of the fundamental material properties of organolead halide perovskite and device operation in varied humidity is still limited . Commercialization of organolead halide perovskite‐based solar cells is very challenging due to their associated stability issues (thermal/photo/moisture/oxygen) despite remarkable efficiency .…”

“…However, the understanding of the fundamental material properties of organolead halide perovskite and device operation in varied humidity is still limited. [14][15][16] Commercialization of organolead halide perovskite-based solar cells is very challenging due to their associated stability issues (thermal/ photo/moisture/oxygen) despite remarkable efficiency. [17][18][19][20] Recently, a protective hole transport material (HTM) has been utilized to prevent atmospheric moisture from entering the perovskite film, which leads to enhanced stability.…”