Efficient p-i-n inorganic CsPbI3 perovskite solar cell deposited using layer-by-layer vacuum deposition

Abstract

Organometallic halide perovskites have emerged as a promising photovoltaic material achieving more than 22% power conversion efficiency. However, poor thermal, environmental, and photostability still plague methyl ammonium based perovskites. Replacing the organic cation with an inorganic cation: Cesium (Cs) is an alternative approach for making thermally stable perovskite solar cells where there is no organic molecule to decompose thermally. In this paper, the authors report on a CsPbI3 perovskite solar cell deposited using a layer-by-layer vacuum deposition technique followed by thermal annealing at 320 °C. A (p type-intrinsic-n type) (p-i-n) device architecture of ITO/polytriaryl amine/CsPbI3/phenyl-C61-butyric acid methyl ester/Al with power conversion efficiency of >10% was achieved by carefully controlling the molar ratios of CsI to PbI2 and the substrate temperature during deposition. The bandgap of the material was 1.74 eV, and the doping density was 2 × 1015/cm3.