Structural stability, optoelectronic properties and solar cell efficiency of the perovskites M₂AgInBr₆(M=K and Rb)

Halide double perovskite materials M 2 AgInBr 6 ([Formula: see text] and Rb) are investigated through density functional theory (DFT) to study the structural and optoelectronic perspective. The calculated electronic properties of M 2 AgInBr 6 reveal that both perovskites are direct bands semiconductors with energy gaps 1.88 and 1.84[Formula: see text]eV, respectively. It is observed that when Rb is replaced through K, the bandgap decreases. Due to direct bandgap, these perovskites are optically active and potential candidates for optical devices and solar cell applications in the visible spectrum. Using fluorine-doped tin-oxide (FTO) as the front contact, the electron transport layer (ETL) of tungsten-disulphide (WS[Formula: see text], hole transport layer (HTL) of molybdenum trioxide (MoO[Formula: see text] and the absorber layer is M 2 AgInBr 6 (M = K and Rb). The optimization of transport layers Cu/MoO 3 /M 2 AgInBr 6 ([Formula: see text] and Rb)/WS 2 /FTO, and the results for solar cell (SC) properties are very useful for photovoltaic applications with [Formula: see text] of 16.48 and 17.62[Formula: see text]mA/cm 2 . The values of [Formula: see text] are 1.21 and 1.19[Formula: see text]V, the values of fill factor are 87.64% and 78.24% and power convergence efficiency is 17.55% and 18.31%, respectively. This study paves the door for future photovoltaics with improved SC performance and experimental development of fully inorganic, lead-free halide double perovskites.