射频磁控溅射制备高In组分Al_(1-x)In_(x)N薄膜及其光学性能

Growth and Optical Properties of In-rich Al_(1-x)In_(x)N Films by Radio-Frequency Magnetron Sputtering

采用射频磁控溅射法,在硅和石英衬底上生长了高In组分Al_(1-x)In_(x)N薄膜。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和紫外-可见-红外分光光度计分别对Al_(1-x)In_(x)N薄膜的结构、形貌和光学带隙进行表征,并在室温下测量Al_(1-x)In_(x)N薄膜的光致发光(PL)谱。结果表明:Al_(1-x)In_(x)N薄膜均呈(002)择优取向,具有单相纤锌矿结构,In组分为x=0.64-0.76。随着In组分升高,薄膜表面更加光滑,光学带隙值由1.93 eV红移至1.87 eV。In组分x=0.64,薄膜以本征发光为主,随着In组分增加,出现了附加的发光峰,这可归因于Moss-Burstein效应。

The In-rich Al_(1-x)In_(x)N films were grown on Si and quartz substrates by radio-frequency magnetron sputtering.The structures,morphologies,and optical bandgap of as-grown Al_(1-x)In_(x)N films were characterized by X-ray diffraction,scanning electron microscopy,and ultra-violate-visible-near infrared spectroscopy.The photoluminescence(PL)spectra of Al_(1-x)In_(x)N films were measured at room temperature.The Al_(1-x)In_(x)N films have single-phase wurtzite structures with(002)preferred orientation.The In content x was tuned in the range of 0.64-0.76.With increasing the In content x,the Al_(1-x)In_(x)N films exhibit smoother surface morphology and the optical bandgap shows a red-shifted from 1.93 eV to 1.87 eV.The PL emission is dominated by the band edge emission at x=0.64.The additional emission could be explained by the Burstein-Moss effect when the In content x was increased.