Enhancing the performance of PbS colloidal quantum dot solar cell: A computational study on absorber crystallinity and interfacial defect engineering

This study utilizes the SCAPS-1D simulator to computationally investigate the effect of absorber layer crystallinity and interfacial properties on the performance of PbS colloidal quantum dot (CQD) solar cell. Crystallinity of the absorber layer is modeled by varying the defect density, while interfacial behavior is analyzed by altering the defect density at the interfaces between the electron transport layer (ETL)/PbS-TBAI, and PbS-TBAI/hole transport layer (HTL). To optimize the efficiency of the PbS-TBAI CQD solar cell, acceptor (N A ) and donor doping (N D ) densities were tailored in the HTL and ETL, respectively. The findings indicate that tuning these parameters is pivotal for enhancing the cell performance. Detailed analysis revealed that the cell performance is strongly influenced by the crystallinity of the PbS-TBAI absorber layer. Additionally, the results demonstrated that the ETL/PbS-TBAI interface plays a more significant role in determining cell efficiency than the PbS-TBAI/HTL interface. Moreover, optimizing the back contact metal is shown to aid in efficient hole transfer by minimizing energy losses, thereby improving overall performance. The optimized solar cell demonstrated an efficiency exceeding 19 %. These findings underscore the importance of fine-tuning key parameters to enhance the efficiency of PbS CQD solar cell. • Achieved over 19 % efficiency in PbS-TBAI CQD solar cells through optimization. • Improved absorber crystallinity to minimize defects and enhance performance. • Engineered interfacial defects to optimize charge transport and reduce losses. • Optimized HTL/ETL doping, boosting efficiency by up to 20 %. • Identified Ni as a cost-effective back contact alternative to Au for better output.