An investigation of hole transport layers and electron transport layers to produce highly efficient K2TiI6-based perovskite solar cells
M. Khalid Hossain, Kazi Md Sadat, Md. Shihab Uddin, Apon Kumar Datta, Prakash Kanjariya, M. Sudhakara Reddy, Rishiv Kalia, Barani Selvaraj, Aboud Ahmed Awadh Bahajjaj, R. Balachandran, Ali Hajjiah, Rajesh Haldhar
Abstract
In this theoretical study, potential K 2 TiI 6 perovskite material has been used as the absorber layer of the investigated perovskite solar cells (PSCs). The SCAPS-1D program was used to conduct the numerical analysis where 10 different hole transport layers (HTLs) and 4 electron transport layers (ETLs) were used to find the best optimum device structure. While various HTLs were studied, D-PBTTT-14 showed the best-optimized performance and therefore it was chosen as the final HTL material for further studies in combination with 4 ETL materials. Different device parameters such as the thickness of the absorber, HTL, and ETL layers; doping concentrations, and defect densities are varied in this work to optimize the investigated device structures. Moreover, the effect of temperature, series and shunt resistance, J-V curve, Q-E curve, recombination and generation rates were explored in this study. After optimizing various device parameters, the device with CdZnS ETL demonstrated superior performance compared to other ETL devices. It achieved a power conversion efficiency (PCE) of 26.21%, fill factor (FF) of 88.06%, short-circuit current density (J sc ) of 20.951 mA/cm², and an open-circuit voltage (V OC ) of 1.4205 V. Under fully optimized conditions, LBSO, Nb 2 O 5 , and PC 60 BM ETL devices showed PCE of 22.06%, 23.24%, and 23.12%, respectively. Based on the findings of this study, it can be stated that this work could be valuable for the practical implementation of K 2 TiI 6 absorber-based PSCs.