文献类型：期刊文献

英文题名：Core/Shell Colloidal Quantum Dot Exciplex States for the Development of Highly Efficient Quantum-Dot-Sensitized Solar Cells

作者：Wang, Jin[1];Mora-Sero, Ivan[2];Pan, Zhenxiao[1];Zhao, Ke[1];Zhang, Hua[1];Feng, Yaoyu[1];Yang, Guang[3,4];Zhong, Xinhua[1];Bisquert, Juan[2]

机构：[1]E China Univ Sci & Technol, Inst Appl Chem, Key Lab Adv Mat, Shanghai 200237, Peoples R China;[2]Univ Jaume 1, Dept Fis, Photovolta & Optoelect Devices Grp, Castellon de La Plana 12071, Spain;[3]Xi An Jiao Tong Univ, Key Lab, Elect Mat Res Lab, Minist Educ, Xian 710049, Peoples R China;[4]Xi An Jiao Tong Univ, Int Ctr Dielect Res, Xian 710049, Peoples R China

年份：2013

卷号：135

期号：42

起止页码：15913

外文期刊名：JOURNAL OF THE AMERICAN CHEMICAL SOCIETY

收录：;EI(收录号：20134416936369);WOS:【SCI-EXPANDED(收录号:WOS:000326215900041)】；

基金：We acknowledge the National Natural Science Foundation of China (no. 21175043), the Science and Technology Commission of Shanghai Municipality (nos. 11JC1403100, 12NM0504101, and 12ZR1407700), and the Fundamental Research Funds for the Central Universities for financial support.

语种：英文

外文关键词：Electrodes - Nanocrystals - Solutions - Quantum efficiency - Semiconductor quantum dots - II-VI semiconductors - Separation - Titanium dioxide - Solar cells

摘要：Searching suitable panchromatic QD sensitizers for expanding the light-harvesting range, accelerating charge separation, and retarding charge recombination is an effective way to improve power conversion efficiency (PCE) of quantum-dot-sensitized solar cells (QDSCs). One possible way to obtain a wide absorption range is to use the exciplex state of a type-II core/shell-structured QDs. In addition, this system could also provide a fast charge separation and low charge-recombination rate. Herein, we report on using a CdTe/CdSe type-II core/shell QD sensitizer with an absorption range extending into the infrared region because of its exciplex state, which is covalently linked to TiO2 mesoporous electrodes by dropping a bifunctional linker molecule mercaptopropionic acid (MPA)-capped QD aqueous solution onto the film electrode. High loading and a uniform distribution of QD sensitizer throughout the film electrode thickness have been confirmed by energy dispersive X-ray (EDX) elemental mapping. The accelerated electron injection and retarded charge-recombination pathway in the built CdTe/CdSe QD cells in comparison with reference CdSe QD-based cells have been confirmed by impedance spectroscopy, fluorescence decay, and intensity-modulated photocurrent/photovoltage spectroscopy (IMPS/IMVS) analysis. With the combination of the high QD loading and intrinsically superior optoelectronic properties of type-II core/shell QD (wide absorption range, fast charge separation, and slow charge recombination), the resulting CdTe/CdSe QD-based regenerative sandwich solar cells exhibit a record PCE of 6.76% (J(sc) = 19.59 mA cm(-2), V-oc = 0.606 V, and FF = 0.569) with a mask around the active film under a full 1 sun illumination (simulated AM 1.5), which is the highest reported to date for liquid-junction QDSCs.