LiGaO_2衬底上ZnO外延膜的结构与光学特性

采用磁控溅射法在(001)、(100)及(010)LiGaO2衬底上制备了ZnO薄膜,通过X射线衍射(XRD)、原子力显微镜(AFM)、透过光谱以及光致发光谱(PL)对薄膜的结构、形貌及光学性质进行了表征。结果表明LiGaO2衬底不同晶面上制备的ZnO薄膜具有不同的择优取向,在(001)(、100)及(010)LiGaO2上分别获得了[0001][、1100]及[1120]取向的ZnO薄膜;不同取向的ZnO薄膜表面形貌差异较大;薄膜在可见光波段具有较高的透过率;在ZnO薄膜的光致发光谱中只观察到了位于378 nm的紫外发射峰,而深能级发射几乎观察不到,(1100)取向的薄膜紫外发射峰强度最大,半高宽也最小,薄膜光致发光性质的差异主要和晶粒尺寸有关。

ZnO films were fabricated on LiGaO<inf>2</inf> (001), (100) and (010) planes by magnetron sputtering. The structural, morphological and optical properties of as-grown ZnO films were investigated by X-ray diffraction (XRD), atomic force microscopy (AFM), transmission spectra and photoluminescence (PL) spectra. The results show that ZnO films on various planes of LiGaO<inf>2</inf> have different preferred orientations. [0001], [11¯00] and [112¯0] oriented ZnO films are obtained on LiGaO<inf>2</inf> (001), (100) and (010) planes, respectively. The ZnO films show different surface morphologies and high transmittance in visible spectrum range. Only UV emission peaks located at 378 nm are observed in PL spectra of ZnO films. The (11¯00) ZnO film shows the highest UV emission intensity with the smallest full width at half maximum (FWHM) value. The difference in PL properties of the ZnO films is mainly due to different grain sizes.