Bengas Rayhena, Lahmar Halla, Redha Khelladi Mohamed, Mentar Loubna, Azizi Amor, Schmerber Guy, Dinia Aziz
Laboratoire de Chimie, Ingénierie Moléculaire et Nanostructures, Université Ferhat Abbas-Sétif 1 Algeria
Research Unit on Nanoscience and Nanotechnology (URNN), Center for the Development of Advanced Technologies (CDTA), Université Ferhat Abbas Sétif 1 19000 Sétif Algeria.
RSC Adv. 2019 Sep 16;9(50):29056-29069. doi: 10.1039/c9ra04670d. eCollection 2019 Sep 13.
Metal oxide p-n heterojunctions consisting of p-CuO/n-ZnO/n-ZnS nanostructures were deposited on an ITO substrate by three-step electrodeposition. The effect of ZnS layer deposition temperature on the properties of the heterojunction was investigated by different techniques. The Mott-Schottky analysis confirmed the n-type conductivity for ZnO and ZnS and p-type conductivity for the CuO layer, respectively. Also, it showed a decrease of ZnS donor concentration with increasing deposition temperature. The X-ray diffraction (XRD) analysis confirms a pure phase of hexagonal ZnO, cubic ZnS and cubic CuO structures, respectively. The heterojunction with ZnS deposited at 60 °C shows high crystallinity. The morphological measurements by scanning electron microscopy (SEM) indicate that the deposition temperature has a significant influence on the morphology of ZnO and the atomic force microscopy (AFM) images revealed the improvement of CuO morphology by increasing the ZnS deposition temperature. The UV-Vis response shows strong absorption in the visible region and the profile of optical absorption spectra changes with the ZnS deposition temperature. The current-voltage (-) characteristics of the Au/p-CuO/n-ZnO/n-ZnS/ITO heterojunction display well-defined rectifying behavior for the heterojunction with ZnS deposited at 60 °C.
通过三步电沉积法将由p-CuO/n-ZnO/n-ZnS纳米结构组成的金属氧化物p-n异质结沉积在ITO衬底上。采用不同技术研究了ZnS层沉积温度对异质结性能的影响。莫特-肖特基分析分别证实了ZnO和ZnS的n型导电性以及CuO层的p型导电性。此外，结果表明随着沉积温度升高，ZnS施主浓度降低。X射线衍射（XRD）分析分别证实了六方ZnO、立方ZnS和立方CuO结构的纯相。在60°C下沉积ZnS的异质结显示出高结晶度。扫描电子显微镜（SEM）进行的形态测量表明，沉积温度对ZnO的形态有显著影响，原子力显微镜（AFM）图像显示，通过提高ZnS沉积温度，CuO的形态得到改善。紫外-可见响应在可见光区域显示出强烈吸收，并且光吸收光谱的轮廓随ZnS沉积温度而变化。对于在60°C下沉积ZnS的异质结，Au/p-CuO/n-ZnO/n-ZnS/ITO异质结的电流-电压（I-V）特性表现出明确的整流行为。
