In Situ Iodide Passivation Toward Efficient CsPbI3 Perovskite Quantum Dot Solar Cells

• Published in: Nano-micro letters Vol. 15; no. 1; p. 163
• Main Authors: Shi, Junwei, Cohen-Kleinstein, Ben, Zhang, Xuliang, Zhao, Chenyu, Zhang, Yong, Ling, Xufeng, Guo, Junjun, Ko, Doo-Hyun, Xu, Baomin, Yuan, Jianyu, Ma, Wanli
• Format: Journal Article
• Language: English
• Published: Singapore Springer Nature Singapore 01-12-2023; Springer Nature B.V; SpringerOpen
• Subjects: Crystal defects; Crystallinity; Crystallography; CsPbI3 perovskite quantum dots; Density; Efficiency; Energy conversion efficiency; Engineering; In situ passivation; Kinetics; Nanoscale Science and Technology; Nanotechnology; Nanotechnology and Microengineering; Nucleation; Optimization; Optoelectronic devices; Perovskite solar cell; Perovskites; Photoluminescence; Photovoltaic cells; Quantum dots; Solar cells; Storage stability; Surface trap states; Synthesis; perovskite quantum dots; CsPbI; Perovskite solar cell; Surface trap states; In situ passivation
• ISSN: 2311-6706; 2150-5551
• DOI: 10.1007/s40820-023-01134-1

Highlights
The introduction of hydroiodic acid (HI) manipulates the dynamic conversion of PbI
2
into highly coordinated species to optimize the nucleation and growth kinetics.
The addition of HI enables the fabrication of CsPbI
3
perovskite quantum dots with reduced defect density, enhanced crystallinity, higher phase purity, and near-unity photoluminescence quantum yield.
The efficiency of CsPbI
3
perovskite quantum dot solar cells was enhanced from 14.07% to 15.72% together with enhanced storage stability.
All-inorganic CsPbI
3
quantum dots (QDs) have demonstrated promising potential in photovoltaic (PV) applications. However, these colloidal perovskites are vulnerable to the deterioration of surface trap states, leading to a degradation in efficiency and stability. To address these issues, a facile yet effective strategy of introducing hydroiodic acid (HI) into the synthesis procedure is established to achieve high-quality QDs and devices. Through an in-depth experimental analysis, the introduction of HI was found to convert PbI
2
into highly coordinated [PbI
m
]
2−m
, enabling control of the nucleation numbers and growth kinetics. Combined optical and structural investigations illustrate that such a synthesis technique is beneficial for achieving enhanced crystallinity and a reduced density of crystallographic defects. Finally, the effect of HI is further reflected on the PV performance. The optimal device demonstrated a significantly improved power conversion efficiency of 15.72% along with enhanced storage stability. This technique illuminates a novel and simple methodology to regulate the formed species during synthesis, shedding light on further understanding solar cell performance, and aiding the design of future novel synthesis protocols for high-performance optoelectronic devices.