以硝酸锌和硝酸钾混和溶液为电解液,采用两电极体系在SnO2:F(FTO)片和p-Si(100)衬底上用不同沉积电压制备了c轴取向的ZnO薄膜。用X-射线衍射、扫描电子显微镜和分光光度计分析了薄膜的相结构,晶粒尺寸和光吸收特性。发现薄膜的(002)衍射峰强度随着沉积电压的增加而显著增强;薄膜中晶粒为典型的六方柱状结构,且基本与衬底垂直,晶粒尺寸为200-400nm;薄膜的光学禁带宽度为3.34eV。光照时,ZnO/Si异质结二极管呈明显的光生电流效应。
A two-electrode electro-deposition system was employed to fabricate c-axis oriented ZnO films on a FTO wafer and p-Si(100) substrate at different voltages by using the Zn(NO3 )/KNO3 mixed solution as the electrolyte. The X-ray diffraction, scanning electron microscopy, and optical spectroscopy were used to analyze the structural properties, the grain size, and the absorption properties of the films. It was found that the (002) peak intensity in XRD patterns increased apparently with the deposition voltage increasing. The grain shape was typically hexa- gonal with the grain size between 200-400 nm, which was almost vertical to the substrate. An optical band gap of 3.34 eV in the films was obtained from the absorption spectra. Under light illumination, the ZnO/Si heterojunetion diode presented a remarkable photocurrent effect.