Department of Chemistry, Hanyang University, Sungdong-Ku, Haengdang-dong 17, Seoul, 133-791, Republic of Korea.
Dalton Trans. 2013 Sep 28;42(36):13065-70. doi: 10.1039/c3dt51149a. Epub 2013 Jul 22.
Photoelectrochemical cells (PECs) of ZnO/CdSe decorated with a charge separating SnO2 nanoparticles (NPs) layer of various thicknesses are prepared and characterized by using scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), UV-visible absorption, energy dispersive X-ray analysis spectroscopy (EDX) and incident photon-to-current conversion efficiency (IPCE) measurements. A uniform coverage of the SnO2 NPs layer over ZnO/CdSe electrode surface is evidenced. The EDX elemental mapping analysis of the ZnO/CdSe/SnO2 PECs demonstrates the presence of Sn and O over the surface. A remarkable improvement in the light harvesting efficiency confirmed from the IPCE measurement, supports an enhancement in current density in the current density-voltage measurement due to increased electron transport and smaller charge recombination. Moreover, these observations are corroborated with the EIS measurement as a cell with SnO2 reveals a reduced charge transfer resistance due to which the power conversion efficiency is increased from 2.20 to 3.41% i.e. 55% compared to the pristine ZnO/CdSe PEC.
光电化学电池（PECs）的 ZnO/CdSe 用电荷分离 SnO2 纳米粒子（NPs）层不同的厚度进行装饰，并通过使用扫描电子显微镜（SEM），电化学阻抗谱（EIS），紫外-可见吸收，能量色散 X 射线分析光谱（EDX）和入射光子-电流转换效率（IPCE）的测量进行了表征。SnO2 NPs 层在 ZnO/CdSe 电极表面的均匀覆盖得到了证实。ZnO/CdSe/SnO2 PECs 的 EDX 元素映射分析表明表面上存在 Sn 和 O。从 IPCE 测量中证实了光捕获效率的显著提高，这支持了电流密度测量中由于电子传输增加和电荷复合减小而导致电流密度的增加。此外，这些观察结果与 EIS 测量相符，因为具有 SnO2 的电池由于电荷转移电阻降低，因此功率转换效率从原始 ZnO/CdSePEC 的 2.20%增加到 3.41%，即增加了 55%。
