Making air-stable all-inorganic perovskite solar cells through dynamic hot-air.

• All-inorganic perovskite solar cells have attracted great interest due to its high thermal stability. • Dynamic hot-air (DHA) assisted method has been used for the deposition of CsPbI 2 Br perovskite thin films. • Alkaline earth metal barium (Ba ²⁺ ) doped CsPbI 2 Br perovskite thin films were sythesized in order to improve its phase stability. • The BaI 2 :CsPbI 2 Br based perovskite devices show average 14.85% power conversion efficiency and maintain >92% initial efficiency over 300 h. • The large area devices exhibited 13.78% efficiency revealed feasibility of this DHA method towards upscalling. • This DHA method facilitates a wide processing window for upscaling the thermally stable inorganic perovskite solar cells. On 3rd August 2019 National Renewable Energy Laboratory (NREL) announced a new world record of 25.2% power conversion efficiency (PCE) for the hottest photovoltaic material known as perovskites. The growth in popularity and substantial improvement in the efficiency of perovskites since their discovery in 2009 is demonstrated by over 6000 publications in 2018. Although, the current world record efficiency has been reported for organic-inorganic halide perovskite, all devices were fabricated in controlled inert conditions and organic cations suffer from poor stability. Therefore, replacement of conventional organic cations by inorganic cations is one of the most promising approaches to make thermally stable photovoltaics. However, all-inorganic perovskite solar cells (PSCs) (herein AIPSCs) composition and deposition techniques limit the real-time stability. This article previews the dynamic hot air (DHA) method used for making CsPbI 2 Br-based perovskites with improved air-thermal stability using barium (Ba²⁺) alkaline earth metal ion doping. Interestingly, the feasibility of this DHA method toward large area fabrication is also demonstrated. [ABSTRACT FROM AUTHOR]