Enhancing charge extraction efficiency in PbS-I quantum dot solar cell through optimized interface engineering

Abstract

Iodine capped lead sulfide colloidal quantum dots (PbS-I-CQDs) offer significant potential for next generation photovoltaics. However, the performance is hampered by nonradiative carriers’ recombination and charge accumulation within the absorbing layer and at interfaces. Here, we employed an interface heterojunction approach by incorporating thin film of ethanedithiol encapsulated lead sulfide (PbS-EDT) quantum dots as HTL between absorbing layer (PbS-I) and carrier collector (Au) to mitigate the challenges. To investigate the photovoltaic performance of PbS-I-CQDs we designed two different device architectures i.e., HTL free (Glass\ITO\ZnO\PbS-I\Au) and HTL incorporated (Glass\ITO\ZnO\PbS-I\PbS-EDT\Au). The results highlight that PCE is significantly enhanced by up to 10.7%, demonstrating that PbS-EDT is most compatible HTL for PbS-I-CQDs based solar cells. PbS-EDT enhances the carrier mobility by minimizing nonradiative carrier recombination and accumulation. The purpose of this study is to search for an ideal HTL for PbS-I-CQDs based solar cells to enhance their photovoltaic performance.