Ikeda Shigeru, Nguyen Thi Hiep, Okamoto Riku, Remeika Mikas, Abdellaoui Imane, Islam Muhammad M, Harada Takashi, Abe Ryu, Sakurai Takeaki
Department of Chemistry, Konan University, 9-1 Okamoto, Higashinada-ku, Kobe, Hyogo 658-8501, Japan.
Institute for Energy Conversion Materials, Konan University, 9-1 Okamoto, Higashinada-ku, Kobe, Hyogo 658-8501, Japan.
Phys Chem Chem Phys. 2021 Dec 22;24(1):468-476. doi: 10.1039/d1cp04075h.
Kesterite CuZnSnS (CZTS) thin films in which the Cu site was partially replaced with Ag were prepared by spray deposition on an Mo-coated glass substrate. Successful replacement of Cu components in the CZTS lattice with Ag up to an Ag/(Cu + Ag) ratio of 0.20 was achieved. Samples with relatively low contents of Ag (Ag/(Cu + Ag) ratios of 0.05 and 0.10) showed obvious grain growth compared to that of bare CZTS, whereas samples with higher Ag contents showed an appreciable decrease in grain sizes. Photoelectrochemical properties for water reduction (H production), which was examined after surface modifications with an InS/CdS double layer and Pt catalyst for H evolution, depended strongly on such morphological differences; a maximum conversion efficiency, , half-cell solar to hydrogen efficiency, of 2.4% was achieved by the photocathode based on the film with an Ag/(Cu + Ag) ratio of 0.10. Minority carrier dynamics examined by photoluminescence measurements indicated that such an active sample of PEC H production had a relatively long carrier lifetime, suggesting that the suppression of carrier recombination at grain boundaries in the bulk of these kesterite films is one of the important factors for enhancing PEC functions.
通过喷雾沉积法在镀钼玻璃基板上制备了铜位点部分被银取代的硫铜锌锡（CZTS）薄膜。成功实现了用银取代CZTS晶格中的铜成分，银/（铜+银）比高达0.20。与纯CZTS相比，银含量相对较低（银/（铜+银）比为0.05和0.10）的样品显示出明显的晶粒生长，而银含量较高的样品晶粒尺寸明显减小。在用InS/CdS双层和用于析氢的铂催化剂进行表面改性后，对水还原（产氢）的光电化学性质进行了研究，其强烈依赖于这种形态差异；基于银/（铜+银）比为0.10的薄膜的光阴极实现了2.4%的最大转换效率（半电池太阳能制氢效率）。通过光致发光测量研究的少数载流子动力学表明，这种用于光电化学产氢的活性样品具有相对较长的载流子寿命，这表明抑制这些硫铜锌锡薄膜本体中晶界处的载流子复合是增强光电化学功能的重要因素之一。
