文献类型：期刊文献

英文题名：Origin of the effects of PEG additives in electrolytes on the performance of quantum dot sensitized solar cells

作者：Sun, Yu[1];Jiang, Guocan[1];Zhou, Mengsi[1];Pan, Zhenxiao[2];Zhong, Xinhua[1,2]

机构：[1]East China Univ Sci & Technol, Sch Chem & Mol Engn, Shanghai 200237, Peoples R China;[2]South China Agr Univ, Coll Mat & Energy, 483 Wushan Rd, Guangzhou 510642, Guangdong, Peoples R China

年份：2018

卷号：8

期号：52

起止页码：29958

外文期刊名：RSC ADVANCES

收录：;EI(收录号：20183605773520);WOS:【SCI-EXPANDED(收录号:WOS:000443624500053)】；

基金：This research is supported by the National Natural Science Foundation of China (NFSC No. 51732004, 91433106, and 21703071)

语种：英文

外文关键词：Indium compounds - Charge transfer - II-VI semiconductors - Zinc compounds - Semiconductor quantum dots - Efficiency - Copper compounds - Nanocrystals - Selenium compounds - Additives - Polyelectrolytes - Electrochemical impedance spectroscopy

摘要：It has been well established that polymer additives in electrolyte can impede the charge recombination processes at the photoanode/electrolyte interface, and improve performance, especially V-oc, of the resulting sensitized solar cells. However, there are few reports about the effect of electrolyte additives on counter electrode (CE) performance. Herein, we systematically investigated the effect of polyethylene glycol (PEG) additives with various molecular weights (M-w from 300 to 20000) in polysulfide electrolyte on the performance of two representative CdSe and Zn-Cu-In-Se (ZCISe) quantum dot sensitized solar cells (QDSCs), and explored the mechanism of the observed effects. Electrochemical impedance spectroscopy measurements indicate that all PEG additives can improve the charge recombination resistance at the photoanode/electrolyte interface, therefore suppressing the unwanted charge recombination process, and enhancing the V-oc of the resulting cell devices accordingly. On the CE side, with the increase of M-w of PEG additives, the initial effect of reducing the charge transfer resistance at the CE/electrolyte interface evolves into an increasing resistance; accordingly the initial positive effect on FF turns into negative one. Accordingly, low M-w PEG can improve efficiency for both CdSe (increasing from 6.81% to 7.60%) and ZCISe QDSCs (increasing from 9.26% to 10.20%). High M-w PEG is still effective for CdSe QDSCs with an efficiency of 7.38%, but falls flat on ZCISe QDSCs (with an efficiency of 9.11%).