High‐Efficiency Infrared Sulfide Lead Quantum Dot Solar Cells via Mixed Halide Ions Ligand Engineering

• DOI: 10.1002/solr.202300804
• Publication Date: 2023-11-21T14:27:39Z
• Authors: Yong Xia; TaiMing Ji; Yu Lu; PengFei Xiang; ZhiXu Wu; XiaoKun Yang; Hui Deng
• Keywords: Passivation; Lead sulfide

Tandem solar cells are regarded as an effective way to break through the theoretical efficiency of Shockley–Queisser limit, and large‐size lead sulfide quantum dots (PbS QDs) considered ideal infrared (IR) photovoltaic materials for absorbing low‐energy IR photons in bottom subcells tandem due their tunable bandgaps multiexciton generation effects. However, exposed (100) surface PbS QDs leads poor passivation during ligand‐exchange process, resulting degraded device performance. Herein, a mixed halide ions ligand strategy is developed synergistically passivate (111) facets QDs. Particularly, gradual dropwise addition chloride salts dissolved dimethyl sulfoxide achieving precisely proportional Cl exchange proposed, which enhances quality QD solids obtains excellent control trap states. Additionally, optical electrical characterization results show that passivated have higher carrier mobility, longer lifetime, lower defect density, increases 1.25%.