Device optimization of all inorganic CsPbBr3/LNMO based multi-layered perovskite light harvesters for broader capturing of solar spectrum

All inorganic Cesium lead bromide (CsPbBr3) planar perovskites have garnered enormous significance in photovoltaic applications owing to its outstanding stability against oxygen, heat and moisture. However, the power conversion efficiencies of the CsPbBr3 planar perovskites are quite low primarily due to the inferior range of light absorbance and interfacial charge recombination losses. This issue can be successfully resolved with a novel multi-absorber architecture approach which incorporates dual absorbers consisting of a lower band gap Lanthanum Nickel Manganese Oxide (La2NiMnO6 or LNMO) material along with the wider band gap CsPbBr3 material so that the light absorbance regime could be well extended for maximal utilization of the solar spectrum. Therefore, this article incorporates numerical modeling and guided optimization of all inorganic ITO/ETL/CsPbBr3/La2NiMnO6(LNMO)/HTL dual absorbers-based heterojunction structure to improvise the power conversion efficiency of CsPbBr3 based single absorber PSCs. The critical device's parameters, such as; absorber layer and carrier transport layer thickness, defect density, temperature, doping concentration, frequency response, capacitance effects, Mott-Schottky effects as well as series and shunt resistances are thoroughly optimized and evaluated using Solar Cell Capacitance Simulator (SCAPS-1D) simulator. The proposed dual absorber layer composition produces a substantial enhancement in performance with a peak power conversion efficiency (PCE) of 26.98 %, short circuit current (J(sc)) of 39.75 mA/cm(2), open circuit voltage (V-oc) of 0.85 V, and fill factor (FF) of 77.98 % at a device defect density of 1015 cm(-3) outperforming the 11 % of PCE attained with the experimentally reported CsPbBr3 single junction counterpart along with PSCs with various dual absorbers-based composition.