講演情報
[15p-K405-7]Over 15% Efficiency of PbS Quantum Dot Solar Cells by Synergistic Effects of Three Interface Engineering
〇YUYAO WEI1, CHAO DING1, DANDAN WANG1, SHUZI HAYASE1, QING SHEN1 (1.Univ. of Electro-Commun.)
キーワード：
quantum dot solar cell、PbS、interface engineering
PbS quantum dot solar cells (QDSCs) are hampered by non-radiative recombination induced by defects and an electron-hole extraction imbalance. Strategies for improve the performance of QDSCs focus on modifying three interfaces: QD/QD, ETL/QD (electron transport layer), and QD/HTL (hole transport layer). However, modifying only one of these interfaces does not fix the problem stated above. In this work, we present coordinated control and passivation of the three interfaces in PbS QDSCs for the first time. It is shown that the synergistic effects help improve charge transport and charge carrier extraction balance and minimize non-radiative recombination simultaneously. We discovered a straightforward approach to epitaxially building an ultrathin perovskite shell layer on the QD surface to passivate the QD/QD interface, resulting in high-quality QD absorber layers with long carrier diffusion lengths. Besides, organic films with adjustable electrical characteristics were introduced to modify the ETL/QD interface, and the effect of the modification on carrier transport and recombination was investigated. The excessive increase in electron extraction rate is found to reduce the fill factor and photovoltaic efficiency at the same time. On this basis, we created a modified layer at the QD/HTL interface to promote hole extraction, which enhanced charge extraction balance and passivated the interface. As a result, PbS CQDSCs based on the synergistic effects of three interface engineering exhibit a PCE of 15.45%, a record for Pb chalcogenide QD solar cells.