Theoretical investigations of all inorganic Cs2SnI6 double perovskite solar cells for efficiency ∼ 30 %.

Vacancy-ordered Cs 2 SnI 6 perovskite as an efficient light harvester sandwiched between the n -ZnO electron transport layer (ETL) and different p-type metal oxides, namely CuBi 2 O 4 , Cu 2 O, CuAlO 2 , and NiO, hole transport layers (HTL) with device architecture of FTO/ZnO/Cs 2 SnI 6 /HTL/Au, a lead-free all inorganic double perovskite solar cells. [Display omitted] • Eco-friendly all inorganic double perovskite solar cells (DPSCs). • Cs 2 SnI 6 double perovskite light harvester and metal oxide charge transport layer. • Ambient stable and highly efficient device with efficiency ∼ 30 %. • Theoretical modelling using SCAPS-1D for high efficiency DPSCs. Non-toxic and air-stable Cesium tin (IV) halide (Cs 2 SnI 6) is a promising alternative to lead halide perovskite for photovoltaic applications. This study reports the extensive analysis of vacancy-ordered Cs 2 SnI 6 perovskite as an efficient light harvester sandwiched between the n -ZnO electron transport layer (ETL) and different p-type metal oxides, namely CuBi 2 O 4 , Cu 2 O, CuAlO 2 , and NiO, hole transport layers (HTL), using SCAPS-1D software. Various physical parameters, viz. thickness, defect density (bulk and interfacial), and charge carrier concentration of different layers for the device architecture of FTO/ZnO/Cs 2 SnI 6 /HTL/Au, are systematically investigated along with the effect of parasitic resistance, work function, and operating temperature in the quest for best device performance in terms of photoconversion efficiency (PCE). The effect of DC biasing voltage is analyzed using C-V characteristics to understand the spatial charge distribution, absorber doping profile, and junction built-in potential. The frequency-dependent admittance was studied using simulated C-f characteristics to give an insight into the defect and the conductance. The Cesium tin (IV) halide (Cs 2 SnI 6) based device optimized with CuBi 2 O 4 , Cu 2 O, CuAlO 2 , and NiO HTLs has shown PCE of 28.18 %, 29.72 %, 29.43 %, and 29.33 %, respectively. [ABSTRACT FROM AUTHOR]