One-Step Preparation and Assembly of Aqueous Colloidal CdSxSe1鈥?i>x Nanocrystals within Mesoporous TiO2 Films for Quantum Dot-Sensitized Solar Cells

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• 作者：Xiaohui Song ; Minqiang Wang ; Jianping Deng ; Zhi Yang ; Chenxin Ran ; Xiangyu Zhang ; Xi Yao
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2013
• 出版时间：June 12, 2013
• 年：2013
• 卷：5
• 期：11
• 页码：5139-5148
• 全文大小：663K
• 年卷期：v.5,no.11(June 12, 2013)
• ISSN：1944-8252

文摘

In the field of quantum dots (QDs)-sensitized solar cells, semiconductor QDs sensitizer with a moderate band gap is required in order to sufficiently match the solar spectrum and achieve efficient charge separation. At present, changing the size of QDs is the main method used for adjusting their band gap through quantum size effect, however, the pore sizes of mesoporous TiO₂ film set a limit on the allowed size of QDs. Therefore, the tuning of electronic and optical properties by changing the particle size could be limited under some circumstances. In this paper, high-quality aqueous CdS_xSe_1鈥?i>x QDs sensitizer is successfully synthesized and effectively deposited on a mesoporous TiO₂ film by a one-step hydrothermal method. In addition to size, alloy QDs provide composition as an additional dimension for tailoring their electronic properties. The alloy composition and band gap can be precisely controlled by tuning the precursor (Se/Na₂S路9H₂O) ratio while maintaining the similar particle size. By using such CdS_xSe_1鈥?i>x sensitized TiO₂ films as photoanodes for solar cell, a maximum power conversion efficiency of 2.23% is achieved under one sun illumination (AM 1.5 G, 100 mW cm^鈥?).

Keywords:

quantum dots-sensitized solar cells; hydrothermal reaction; compositional tuning; cadmium sulfide selenide; titanium dioxide