文献类型：期刊文献

英文题名：CdSeTe/CdS Type-I Core/Shell Quantum Dot Sensitized Solar Cells with Efficiency over 9%

作者：Yang, Junwei[1];Wang, Jin[1];Zhao, Ke[1];Izuishi, Takuya[2];Li, Yan[1];Shen, Qing[2];Zhong, Xinhua[1]

机构：[1]E China Univ Sci & Technol, Inst Appl Chem, Key Lab Adv Mat, Shanghai 200237, Peoples R China;[2]Univ Electrocommun, Dept Engn Sci, Chofu, Tokyo 1828585, Japan

年份：2015

卷号：119

期号：52

起止页码：28800

外文期刊名：JOURNAL OF PHYSICAL CHEMISTRY C

收录：;EI(收录号：20160201782995);WOS:【SCI-EXPANDED(收录号:WOS:000367704500013)】；

基金：This research is supported by the Natural Science Foundation of China (nos. 21421004, 91433106, and 21301059), the Open Project of State Key Laboratory of Chemical Engineering (SKL-ChE-14C04), and the Fundamental Research Funds for the Central Universities in China. Q. S. thanks the support of MEXT KAKENHI Grant Number 26286013 and the CREST program, Japan Science and Technology Agency (JST).

语种：英文

外文关键词：Shells (structures) - Coremaking - II-VI semiconductors - Nanocrystals - Titanium dioxide - Open circuit voltage - Semiconductor quantum dots - Silica - Electrochemical impedance spectroscopy - Quantum efficiency - Surface defects - Cadmium sulfide solar cells - Energy gap - Selenium compounds

摘要：Surface trap defects are the limited factor for quantum dots (QDs) application in solar cells. The trapping states can be efficiently suppressed by coating a shell of wider band gap material around the core QDs. We choose CdSe0.65Te0.35 (simplified as CdSeTe) as a model core material, and CdS shell was then overcoated around the CdSeTe core QD to decrease surface defect density and to increase the stability of the core QDs. By optimizing the thickness of the CdS shell, the power conversion efficiency (PCE) of the CdSeTe/CdS quantum dots sensitized solar cells (QDSCs) is enhanced by 13% in comparison with that of plain CdSeTe QDSCs. Transient absorption (TA), incident-photo-to-carrier conversion efficiency (IPCE), open-circuit voltage decay (OVCD), and electrochemical impedance spectroscopy (EIS) measurements confirmed the suppressed charge recombination process in internal QDs and QD/TiO2/electrolyte interfaces with the overcoating of CdS shell around CdSeTe core QDs. With the further overcoating of a-TiO2 and SiO2 barrier layers around the QD-sensitized photoanode, the PCE of champion CdSeTe QDSCs achieved 9.48% (Jsc = 20.82 mA/cm(2), V-oc = 0.713 V, FF = 0.639) with average PCE 9.39 + 0.09% under AM 1.5 G one full sun illumination.