Facile one-step fabrication of CdS0.12Se0.88 quantum dots with a ZnSe/ZnS-passivation layer for highly efficient quantum dot sensitized solar cells
Facile one-step fabrication of CdS0.12Se0.88 quantum dots with a ZnSe/ZnS-passivation layer for highly efficient quantum dot sensitized solar cells
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轻松一步制造带有 ZnSe/ZnS 钝化层的 CdS0.12Se0.88 量子点，用于高效量子点敏化太阳能电池
DOI：
10.1039/c8ta01048j
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发表时间：
2018-06-07
影响因子：
11.9
通讯作者：
Cao, Guozhong
中科院分区：
文献类型：
--
作者：
Hou, Juan;Zhao, Haifeng;Cao, Guozhong
采用一锅连续离子层吸附反应（SILAR）法，在具有ZnSe/ZnS钝化层的TiO 2光阳极上首次合成了带隙可调的CdS 0.12Se 0.88量子点敏化剂（简称CSS（ZSS））.实现了高达6.14%的高功率转换效率（PCE）（Jsc = 20.4 mA cm-2，Voc = 578 mV，FF = 0.52），这几乎是在阳离子溶液中没有Zn 2+进料的量子点敏化太阳能电池（QDSC）的效率3.40%的两倍。结果表明，光吸收增强以及光学带隙变化（从2.13 eV到1.89 eV）有效地促进了光捕获，导致光电流密度增加。一个仔细的控制的Zn/Cd的摩尔比的SILAR周期起着至关重要的作用，在确定JSC和Voc，并讨论了可能的解释和机制。量子点和电解质之间的界面处的电荷复合也进行了阐述。
Bandgap-tunable alloyed CdS0.12Se0.88 quantum dot (QD) sensitizers on a TiO2 photoanode with a ZnSe/ZnS passivation layer (denoted as CSS(ZSS)) were successfully synthesized for the first time by a facile one-pot successive ionic layer adsorption and reaction (SILAR) process from a cationic solution containing Zn2+ and Cd2+, and an anionic solution containing Se2− and S2−. A high power conversion efficiency (PCE) up to 6.14% (Jsc = 20.4 mA cm−2, Voc = 578 mV, FF = 0.52) was achieved, which is almost double the efficiency of 3.40% for the quantum dot sensitized solar cells (QDSCs) without Zn2+ feeding in the cationic solution. The results indicated that the light absorbance enhancement as well as the optical bandgap variation (from 2.13 eV to 1.89 eV) effectively promoted the light harvesting, leading to an increased photocurrent density. A careful control of the molar ratio of Zn/Cd by the SILAR cycles played a vital role in determining Jsc and Voc, and the possible explanation and mechanisms are discussed. The charge recombination at the interface between the QDs and electrolyte was also elaborated.