Microsphere Light-Scattering Layer Assembled by ZnO Nanosheets for the Construction of High Efficiency (>5%) Quantum Dots Sensitized Solar Cells

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• 作者：Jianjun Tian ; Lili Lv ; Xuyang Wang ; Chengbin Fei ; Xiaoguang Liu ; Zhenxuan Zhao ; Yajie Wang ; Guozhong Cao
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：July 31, 2014
• 年：2014
• 卷：118
• 期：30
• 页码：16611-16617
• 全文大小：463K
• ISSN：1932-7455

文摘

This work reported on a bilayer photoelectrode constructed by ZnO nanoparticle (NP) film and ZnO microsphere (MS) scattering layer for CdS/CdSe quantum dot cosensitized solar cells (QDSCs) with a power conversion efficiency (PCE) of greater than 5%. We controlled the growth orientations of ZnO crystals to form nanosheets, which attached together and assembled into MS due to the high surface energy of the nanosheets. MSs were used as a top layer to effectively increase the light diffuse reflection and harvesting to enhance photogenerated current. In comparison with ZnO NPs photoelectrode, the short circuit current density (J_sc) of ZnO NPs/MSs photoelectrode increased from 10.3 mA/cm² to 16.0 mA/cm², which was an enhancement of 55%. To further increase the fill factor and PCE of QDSCs, ZnO NPs/MSs was treated in the solution of H₃BO₃ and (NH₄)₂TiF₆ to form a barrier surface layer, which suppressed the charge recombination and prolonged electron lifetime. As a result, the solar cell displayed J_sc of 17.13 mA/cm², V_oc of 0.56 V, FF of 0.53, and PCE of 5.08%, one of the highest values for ZnO-based QDSCs at this time.