Effects of Cr2O3 modification on the performance of SnO2 electrodes in DSSCs.
Effects of Cr2O3 modification on the performance of SnO2 electrodes in DSSCs.
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DOI：
10.1039/c2cp23545e
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发表时间：
2012-02
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影响因子：
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通讯作者：
Seo-Yeong Choi;Min-Hye Kim;Young-Uk Kwon
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文献类型：
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作者：
Seo-Yeong Choi;Min-Hye Kim;Young-Uk Kwon
在本文中，我们证明了Cr（2）O（3），可见光吸收绝缘体，可以用作染料敏化太阳能电池（DSSC）的阳极的有效的阻挡层材料。制备了不同Cr/Sn比的Cr2 O3表面修饰的SnO 2电极，研究了表面修饰对DSSC性能的影响。Cr/Sn比为0.02、0.05和0.10的DSSC显示出比纯SnO（2）提高的总体光电转换效率。特别地，Cr/Sn比为0.02的DSSC表现出55%的显著大的增加。通过粉末X射线衍射、透射电子显微镜、N（2）吸附研究和UV-Vis漫反射光谱对电极材料进行分析。含Cr物种表现为Cr（2）O（3）纳米颗粒，均匀地分布在SnO（2）纳米颗粒上，填充SnO（2）颗粒之间的差距空间。用Mott-Schottky曲线和电化学阻抗谱表征了电极的电化学性能。随着Cr含量的增加，平带电位负移。阻抗谱数据表明，Cr/Sn = 0.02和0.05的样品在电极处具有较低的电荷传输电阻，这可以通过电荷从更碱性的Cr（2）O（3）纳米颗粒转移到SnO（2）纳米颗粒而导致导电水平的升高来解释。这些观察结果证实了DSSC的短路电流和开路电压的趋势。
In this paper, we demonstrate that Cr(2)O(3), a visible absorbing insulator, can be used as an efficient blocking layer material for the anode of dye-sensitized solar cells (DSSCs). We prepared SnO(2) electrodes surface-modified with Cr(2)O(3) with various Cr/Sn ratios and studied the effect of the modification on the performance of DSSCs. DSSCs with Cr/Sn ratios 0.02, 0.05, and 0.10 showed increased overall photon-to-electricity conversion efficiency from that of pure SnO(2). Especially, the DSSC with the Cr/Sn ratio 0.02 showed a remarkably large increase by 55%. The electrode materials were analyzed by powder X-ray diffraction, transmission electron microscopy, N(2) adsorption studies, and UV-Vis diffuse reflectance spectroscopy. The Cr-containing species appears to be Cr(2)O(3) nanoparticles, spread evenly on the SnO(2) nanoparticles and filling the gap space between SnO(2) particles. The electrochemical properties of the electrodes were characterized by Mott-Schottky plots and electrochemical impedance spectroscopy. As the Cr-content increases, the flat-band potential is negatively shifted. The impedance spectroscopy data show that Cr/Sn = 0.02 and 0.05 samples have lower charge transport resistance at the electrode, which can be explained by the rise of the conduction level due to the charge transfer from the more basic Cr(2)O(3) nanoparticles to SnO(2) nanoparticles. These observations corroborate with the trends of the short-circuit current and the open-circuit voltage of the DSSCs.