10.6% Certified Colloidal Quantum Dot Solar Cells via Solvent-Polarity-Engineered Halide Passivation

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• 作者：Xinzheng Lan ; Oleksandr Voznyy ; F. Pelayo García de Arquer ; Mengxia Liu ; Jixian Xu ; Andrew H. Proppe ; Grant Walters ; Fengjia Fan ; Hairen Tan ; Min Liu ; Zhenyu Yang ; Sjoerd Hoogland ; Edward H. Sargent
• 刊名：Nano Letters
• 出版年：2016
• 出版时间：July 13, 2016
• 年：2016
• 卷：16
• 期：7
• 页码：4630-4634
• 全文大小：366K
• 年卷期：0
• ISSN：1530-6992

文摘

Colloidal quantum dot (CQD) solar cells are solution-processed photovoltaics with broad spectral absorption tunability. Major advances in their efficiency have been made via improved CQD surface passivation and device architectures with enhanced charge carrier collection. Herein, we demonstrate a new strategy to improve further the passivation of CQDs starting from the solution phase. A cosolvent system is employed to tune the solvent polarity in order to achieve the solvation of methylammonium iodide (MAI) and the dispersion of hydrophobic PbS CQDs simultaneously in a homogeneous phase, otherwise not achieved in a single solvent. This process enables MAI to access the CQDs to confer improved passivation. This, in turn, allows for efficient charge extraction from a thicker photoactive layer device, leading to a certified solar cell power conversion efficiency of 10.6%, a new certified record in CQD photovoltaics.