Micro structurally engineered hysteresis-free high efficiency perovskite solar cell using Zr-doped TiO2 electron transport layer. Issue 10 (15th May 2021) - Sandhu, Sanjay
Abstract: The high trap-state density and low conductivity in compact TiO2 (c-TiO2 ) layer limits the power conversion efficiency (PCE) of organic-inorganic hybrid perovskite solar cells (HPSCs). Metal doping in c-TiO2 has been proven to be a successful strategy for enhancing the PCE of HPSCs. Herein, Zr is incorporated in the c-TiO2 layer with different doping concentrations, and its impact on the photovoltaic performance of methylammonium lead iodide (MAPbI3 ) HPSCs is investigated. Inclusion of Zr enhances the charge carrier collection at TiO2 /perovskite junction as well as conductivity of TiO2 layer. It is demonstrated that Zr-doping reduces the dark current significantly by suppressing non-geminated recombinations, leakage path, and electron trap-states. As a result, the HPSCs with optimum Zr-doping (10 vol%) exhibits open-circuit voltage ( V OC ) of 1.076 V, short-circuit current density ( J SC ) of 23.57 mA cm −2, and PCE of 18.16% under one-sun illumination conditions. UV absorption confirms the increase in bandgap upon Zr-doping that leads to favorable band alignment with the perovskite layer. Further, the engineered solar cells are probed for current density-voltage ( J - V ) hysteresis, operational stability, leakage current, intensity-dependence behavior, and electrochemical impedance spectroscopy (EIS).