Device modelling of lead free (CH3NH3)2CuX4 based perovskite solar cells using SCAPS simulation

The Copper (Cu)-based perovskite materials, (CH3NH3)2CuX4 or (MA)2CuX4 with [X = Cl4, Cl2I2, and Cl2Br2] are explored for use in perovskite solar cells (PSCs). The foremost objectives of this investigation are the optimization and finding the combination of Electron Transport Layer [ETL], Perovskite Absorber Layer (PAL) and the different organic and inorganic Hole Transport Layers [HTLs] for better device performance. The impact of other important functional parameters on the performance of PSCs are also studied. These parameters are, thicknesses of PAL, operating temperature (T), series resistance (RS), and radiative recombination rate under the illuminance of AM1.5. This SCAPS-1D simulation study deduced the optimized value of the thickness for (MA)2CuCl4, (MA)2CuCl2I2 and (MA)2CuCl2Br2 based absorber layer to be 400 nm, 500 nm and 600 nm, respectively at defect density (Nt) of 1 × 1013 cm−3 and 300 K operating temperature. The optimum value of operating temperature is 300 K for all PSCs but for C60/(MA)2CuCl4/Cu2O PSC, optimum value is 320 K at 400 nm of absorber layer. With considerations of all these optimum values, the highest power conversion efficiency of 28.31% has been obtained for the PCBM/(MA)2CuCl2Br2/CuI configuration at operating temperature of 300 K. Thus, the study reveals that PCBM as ETL, while CuI and Cu2O as HTLs are most suitable for the Cu-based PSC. Based upon the comparison with experimental results, our findings are indicative of the fact that traditional charge transport materials like TiO2 and spiro-OMeTAD may not be the best choices for new lead-free Cu-based PSCs.