Preparation and Properties of GaN Micro-Ribbons on Ga-Diffused Si （111） Substrates

Preparation and Properties of GaN Micro-Ribbons on Ga-Diffused Si (111) Substrates

摘要:

用射频磁控溅射工艺在室温扩镓硅衬底上沉积Ga2O3膜,然后在氨气气氛下氮化Ga2O3膜得到GaN微米带,用X射线衍射(XRD)、扫描电镜(SEM)、选区电子衍射(SAED)、X射线光电子能谱(XPS)及光致发光谱(PL)对薄膜样品进行了结构、表面形貌、组分及发光特性分析.SEM图像显示直径约为100 nm～300 nm微米带随机分布在GaN薄膜表面.XRD、XPS及SAED分析表明GaN微米带呈六方闪锌矿多晶结构,择优沿[001]方向生长.P1显示了可能由量子限制效应引起的发光峰,其相对于报道的GaN晶体发光峰有显著蓝移.

Abstract:

Hexagonal GaN micro-ribbons were synthesized through nitriding Ga2O3 films under flowing ammonia. Ga2O3 films were deposited on the Ga-diffused Si (111) substrates by radio frequency (r.f.) magnetron sputtering. X-ray diffraction (XRD), scanning electron microscopy (SEM), selected area electron diffraction (SAED); X-ray photo electronic spectrometer (XPS) and photoluminescence (PL) spectroscopy were used to characterize the structure, surface morphology, composition and optical property of the synthesized samples. SEM images show that GaN micro-ribbons with 100-300rim in diameter are randomly distributed on the uniform films. XRD, XPS and SAED analysis suggest the micro-ribbons are polycrystalline GaN with hexagonal structure and preferentially grow in the [001] direction. The PL spectrum has a remarkable blue shift compared with the reported values of bulk GaN, which might be ascribed to quantum confinement effects.