Quantum dot solar cells (QDSCs) have recently attracted a lot of interest since the materials used in them are eco-friendly, good light harvesters, and cheap. Solar Cell Capacitance Simulator-1 dimensional software (SCAPS-1D) is used to carry out this numerical analysis. In the present work, the optimization of two different device architectures is investigated having WO 3 and WS 2 two different electron transport layer(ETL). In the proposed device structure, Sb 2 Se 3 is used as an absorber layer and PbS is used as HTL and CdS is used as a buffer layer. The main objective of this effort is to determine how changing from the WO 3 ETL to the WS 2 ETL affects the photovoltaic parameters. Initially, the solar photovoltaic device is optimized, and then the effect of doping concentrations is investigated. In addition, the effect of series and shunt resistance on the solar device's performance is examined to illustrate the impact of series and shunt resistance on the device's performance. The effect of increasing temperature on the PV parameters is also studied and it is observed that the solar device is temperature-sensitive. Finally, the optimized performance with WS 2 ETL with PCE of 20.60% is achieved.Author contributions: Naureen, Sadanand and Shambhavi Rai analyze the device structure, simulation study and drafted the manuscript. R.K.Yadav, Pooja Lohia and D.K. Dwivedi updated the draft le of manuscript.