Interface engineering for improved performance of perovskite solar cells using CdTe buffer layer

In order to achieve high power conversion efficiency, interface engineering of the charge transport layers in perovskite solar cells (PSCs) has significantly reduced the energy band mismatching and charge accumulation. This simulation study investigated the effect of cadmium telluride (CdTe) buffer layer (BL) on the performance of PSC through SCAPS-1D modeling program. The device configuration with BL consisted of metal electrode/CuI/CdTe/CH3NH3SnI3/TiO2/TCO/glass substrate. The insertion of BL between absorber and HTM improved the energy band alignment by increasing the power conversion efficiency (PCE) from 11.09 % to 14.76 %. The important parameters including thicknesses of the buffer and absorber layers, the doping concentrations of absorber, electron transport material (ETM), and hole transport material (HTM) were investigated. Moreover, the effect of the electron affinity of the ETM, HTM and the hole mobility of HTM were optimized to further enhance the performance of the proposed structure. The optimized results showed the noticeable increase in efficiency of 23.56 %.