Highly Efficient Flexible Perovskite Solar Cells through Pentylammonium Acetate Modification with Certified Efficiency of 23.35%

Abstract

Among the emerging photovoltaic technologies, rigid perovskite solar cells (PSCs) have made tremendous development owing to their exceptional power conversion efficiency (PCE) of up to 25.7%. However, the record PCE of flexible PSCs (≈22.4%) still lags far behind their rigid counterparts and their mechanical stabilities are also not satisfactory. Herein, through modifying the interface between perovskite and hole transport layer via pentylammonium acetate (PenAAc) molecule a highly efficient and stable flexible inverted PSC is reported. Through synthetic manipulation of anion and cation, it is shown that the PenA+ and Ac− have strong chemical binding with both acceptor and donor defects of surface‐terminating ends on perovskite films. The PenAAc‐modified flexible PSCs achieve a record PCE of 23.68% (0.08 cm2, certified: 23.35%) with a high open‐circuit voltage (VOC) of 1.17 V. Large‐area devices (1.0 cm2) also realized an exceptional PCE of 21.52%. Moreover, the fabricated devices show excellent stability under mechanical bending, with PCE remaining above 91% of the original PCE even after 5000 bends.

Toxicity, Leakage, and Recycling of Lead in Perovskite Photovoltaics

“…Since perovskite photovoltaics pursue high photoelectric conversion efficiency and outstanding stability, A-site in the commonly used perovskite is formamidinium (FA) doped with methylamine (MA) and Cs, B-site is Pb, and the halogen-site is mainly iodine doped with bromine and chlorine. [107][108] Such perovskite possesses suitable band gap, excellent PCE, and satisfactory stability. Therefore, FAPbI 3 -based perovskites are widely used in high-performance perovskite photovoltaics.…”

Amorphous F‐doped TiOx Caulked SnO2 Electron Transport Layer for Flexible Perovskite Solar Cells with Efficiency Exceeding 22.5%

“…[12,13] Hence it will be difficult to achieve their optimum charge transport performance, which becomes an important reason for the efficiency gap between f-PSCs and rigid PSCs. [14][15][16][17][18][19] Whether at the ETL/MHP interface or within the ETL, the enhancement in transporting and extraction of ETL-based photogenerated electrons has become a vital strategy to further improve the PCE and long-term stability of PSCs. Currently, tin(IV) oxide (SnO 2 ) has been demonstrated as an excellent electron transport layer (ETL) due to its favorable low-temperature processability, and wide bandgap with high optical transmittance in the visible light range, suitable band alignment with commonly used MHP absorbers, and decent chemical stability.…”

Backbone Engineering Enables Highly Efficient Polymer Hole‐Transporting Materials for Inverted Perovskite Solar Cells

“…[1][2][3][4][5][6][7][8][9][10][11] In comparison with the conventional (n-i-p) PVSCs, inverted (p-i-n) PVSCs possessed the merits of low-temperature processability and more promising operational stability, [12][13][14][15] enabling the suitability for wearable electronics and large-area fabrication. [16][17][18][19][20][21] Nevertheless, despite the fact that the highest PCE of inverted PVSCs (25.37%) has been boosted to be close to the conventional ones, an efficiency gap remains to be eliminated. [20,[22][23][24][25][26] The interfaces and perovskite crystallinity play a critical role in determining device…”