Polymer‐Passivated Inorganic Cesium Lead Mixed‐Halide Perovskites for Stable and Efficient Solar Cells with High Open‐Circuit Voltage over 1.3 V

Abstract

Cesium-based trihalide perovskites have been demonstrated as promising light absorbers for photovoltaic applications due to their superb composition stability. However, the large energy losses (E ) observed in inorganic perovskite solar cells has become a major hindrance impairing the ultimate efficiency. Here, an effective and reproducible method of modifying the interface between a CsPbI Br absorber and polythiophene hole-acceptor to minimize the E is reported. It is demonstrated that polythiophene, deposited on the top of CsPbI Br, can significantly reduce electron-hole recombination within the perovskite, which is due to the electronic passivation of surface defect states. In addition, the interfacial properties are improved by a simple annealing process, leading to significantly reduced energy disorder in polythiophene and enhanced hole-injection into the hole-acceptor. Consequently, one of the highest power conversion efficiency (PCE) of 12.02% from a reverse scan in inorganic mixed-halide perovskite solar cells is obtained. Modifying the perovskite films with annealing polythiophene enables an open-circuit voltage (V ) of up to 1.32 V and E of down to 0.5 eV, which both are the optimal values reported among cesium-lead mixed-halide perovskite solar cells to date. This method provides a new route to further improve the efficiency of perovskite solar cells by minimizing the E .

Morphology Controlling of All‐Inorganic Perovskite at Low Temperature for Efficient Rigid and Flexible Solar Cells

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organic components with inorganic cations such as cesium (Cs + ) and rubidium (Rb + ) ions can effectively improve the thermal stability. [24][25][26][27][28][29][30] To improve the performance of CsPbX 3 -based PSCs, a series of work on composition [18,19] and fabrication [20][21][22][23][24] engineerings have been intensely carried out. The CsPbI 2 Br perovskites, which possess a reasonable bandgap of 1.9 eV and considerable phase stability, were emphasized as the main research subject in previous work.

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“…Recently, all-inorganic cesium lead halide perovskites (CsPbX 3 , X = I, Br, Cl, or mixed halides), which have higher melting points (in excess of 460 °C), [10] have been investigated as thermal stable photoabsorption materials. Unfortunately, the CsPbX 3 perovskites generally require high-temperature annealing (>250 °C) to form black photovoltaic-active cubic phase, [27][28][29][30] which is energy-consuming and undesirable for multijunction tandem and flexible solar cells. [24][25][26][27][28][29][30] To improve the performance of CsPbX 3 -based PSCs, a series of work on composition [18,19] and fabrication [20][21][22][23][24] engineerings have been intensely carried out.…”

Surface Trap States Passivation for High‐Performance Inorganic Perovskite Solar Cells

“…CsPbBr 3 and CsPbIBr 2 show high‐moisture‐sustained properties, but the narrow range of light absorption spectrum limits their utilization as light harvesting materials. CsPbI 2 Br will be a potential candidate among the cesium lead trihalides perovskites due to its available bandgap of 1.91 eV and good operability in ambient atmosphere …”

Anorganische CsPbX3‐Perowskit‐Solarzellen: Fortschritte und Perspektiven

“…[182,183] [185] 9.5 %s PCE und rfV OC % 1.28 Vwurden erreicht. [182,183] [185] 9.5 %s PCE und rfV OC % 1.28 Vwurden erreicht.…”