核-壳结构ZnO@CuO光阳极的制备及其光电性能研究

Preparation and Photoelectric Properties of Core-Shell ZnO@CuO Photoanode

摘要:

ZnO是钙钛矿太阳电池(PSCs)电子传输层(ETL)的优良材料,但ZnO与钙钛矿吸收层界面有很大的热不稳定性,从而导致该界面严重的电荷复合。文章采用水热法在FTO导电玻璃上制备出具有良好取向性的ZnO纳米棒阵列(NAs)。通过调控电化学沉积时间,在ZnO NAs上沉积一层CuO纳米颗粒,获得ZnO@CuO纳米复合材料薄膜。利用场发射扫描电镜(FESEM)、X射线衍射(XRD)对复合薄膜的形貌和物相进行了观察和分析。通过紫外-可见光漫反射(UV-Vis DRS)和瞬态荧光光谱(PL)对其光学性能进行了测定。结果表明,制备的ZnO NAs阵列均匀且垂直度较好,直径约为120nm；通过电化学沉积CuO纳米颗粒(尺寸为34~44nm)后,复合薄膜的可见光吸收能力增强,载流子分离效率提高；在电化学沉积时间为40s时,所得到的ZnO@CuO NAs的光电流密度最高,约为ZnO NAs的3.37倍,表现出良好的光电转换性能。

Abstract:

ZnO is an excellent material for the electron transport layer (ETL) of perovskite solar cells (PSCs), but the interface between ZnO and perovskite absorption layer has great thermal instability, resulting in serious charge recombination at the interface. In this paper, ZnO nanorod arrays (NAs) with good orientation were prepared on FTO conductive glass by hydrothermal method. By adjusting the electrodeposition time, a layer of CuO nanoparticles was electrodeposited on ZnO NAs, and ZnO@CuO nanocomposite films were obtained. The morphology and phase of the composite films were observed and analyzed by field emission scanning electron microscope (FESEM) and X-ray diffraction (XRD). The optical properties were measured by UV-visible diffuse reflectance (UV-vis DRS) and transient fluorescence spectroscopy (PL). The results show that ZnO NAs is uniform with good perpendicularity, and the diameter is about 120nm. After electrodeposition of CuO nanoparticles (size between 34nm and 44nm), the visible light absorption capacity of the composite film is enhanced, and the carrier separation efficiency is improved. When the electrodeposition time is 40s, ZnO@CuO NAs have the largest photocurrent density which is about 3.37 times that of ZnO NAs, showing good photoelectric conversion performance.