Tailored Phase Transformation of CsPbI₂Br Films by Copper(II) Bromide for High-Performance All-Inorganic Perovskite Solar Cells

Abstract

All-inorganic-based perovskites achieved by replacing the organic component with cesium (Cs) have drawn more attention because of their intrinsic inorganic stability. However, the cell efficiency in all-inorganic perovskite solar cells is still far below that in organic–inorganic hybrid perovskite-based devices. Here, we develop a new strategy to mediate the CsPbI2Br crystallization by directly doping copper­(II) bromide (CuBr2) into a perovskite precursor. The incorporation of CuBr2 played a role in retarding the crystallization dynamics process of CsPbI2Br film, resulting in a high-quality all-inorganic perovskite film with enlarged grain size, improved carrier mobilities, and reduced trap states. The fabricated perovskite solar cells delivered a champion power conversion efficiency of 16.15%, which is the highest efficiency in CsPbI2Br based all-inorganic perovskite solar cells and largely higher than 13.24% for pristine CsPbI2Br based device. The developed doping method paves a new route to fabricate high-performance all-inorganic perovskite solar cells.

Inorganic Halide Perovskite Solar Cells: Progress and Challenges

“…Reproduced with permission. [ 104 ] Copyright 2019, American Association for the Advancement of Science. e) Schematic mechanism for dimethylammonium iodine (DMAI) additive induced black phase CsPbI 3 formation.…”

“…Reproduced with permission. [ 104 ] Copyright 2019, American Association for the Advancement of Science.…”

“…Reproduced with permission. [ 96,97,99,101,102,104,105,107 ] Copyright 2017, ACS. Copyright 2018, Wiley.…”

Guanidinium Passivation for Air‐Stable Rubidium‐Incorporated Cs(1 − x)RbxPbI2Br Inorganic Perovskite Solar Cells

“…In particular, CsPbI 2 Br perovskite has been considered as a potential candidate for inorganic PSC due to its reasonable bandgap (≈1.9 eV) and much improved ambient stability . However, it is still structurally unstable and can easily transform into nonperovskite orthorhombic phase under prolonged exposure to high humidity . Therefore, it is imperative to explore new strategies to develop more stable and efficient CsPbI 2 Br perovskite.…”

A facile surface passivation method for efficient inorganic CsPbI2Br perovskite solar cells with efficiencies over 15%

“…Unlike CsPbIBr 2 and CsPbI 3 , CsPbI 2 Br is able to achieve both good light-harvesting ability and good phase stability, suggesting that CsPbI 2 Br is a promising active-layer material for PVSCs with its good balance between the efficiency and stability. In recent two years, many strategies have been reported for the fabrication of high-performance CsPbI 2 Br-based PVSCs [11,12,[19][20][21][22][23].…”