Efficient Ruddlesden-popper (RP) perovskites as electron selective layers yielding over 20 % efficiency in MAPb(I1-xClx)3 based organic-inorganic perovskite solar cells: A DFT and SCAPS-1D investigations

The electron transport layer (ETL) is linchpin in perovskite solar cells (PSCs). It offers potent and discriminatory electron elicitation, minute resistivity, and lofty strength along with optimal device performance. In this study combined DFT and SCAPS-1D framework are used to investigate the optimized designs of CH 3 NH 3 Pb(I 1-x Cl x ) 3 organic-inorganic perovskite-based solar cells. The analysis of structural stability, mechanical strength and optoelectronic traits was done by employing first-principle calculations with three different exchange-correlation functionals for A 2 SnO 4 (A = Sr, Ba) Ruddlesden-popper (RP) compounds. SCAPS-1D was used to analyze device performance by employing different ETLs in PSC architecture. The structural analysis reveal that Sr 2 SnO 4 possesses a more stable structure in tetragonal phase with space group I 4/ mmm (139) than Ba 2 SnO 4 . Mechanical stability is corroborated through the reckoning of elastic constants, with Sr-based RP perovskite showing better mechanical properties as compared to Ba-based RP perovskite enunciating it auspicious for device fabrication. Electronic properties, analyzed through the band structure (BS) and density of state (DOS), confirm the semiconducting nature of both materials, with indirect band gap of 4.59 eV (Ba 2 SnO 4 ) and 4.21 eV (Sr 2 SnO 4 ). The optical analysis has stipulated that both materials are found to be good absorbers of ultraviolet (UV) radiation. An optimized device FTO/Sr 2 SnO 4 /MAPb(I 1-x Cl x ) 3 /Cu 2 O/Au is contemplated here with an open-circuit voltage ( V o c ) of 1.257 V, a short-circuit current ( J s c ) of 23.06 m A / c m 2 , fill factors ( F F ) of 83.57 %, and a theoretical power conversion efficiency ( P C E ) of 24.25 %. Overall, our findings reveal that Sr 2 SnO 4 RP material have promising and potential features as a novel ETL material for employment in organic-inorganic PSC as a source of renewable energy.