SiC衬底上异质外延GaN薄膜XPS谱和PL谱研究

XPS and PL Studies of GaN Epilayers Grown on SiC Substrate

利用X射线光电子能谱 ,对在SiC衬底上采用MOCVD异质外延的未故意掺杂的GaN进行N、Ga组份测试 ,同时用光致发光技术对样品进行发光特性的研究 结果表明 ,随着GaN薄膜中Ga百分含量逐渐减小 ,室温下黄光输出峰值强度却逐渐增加 因此 ,在Ga含量相对低的GaN薄膜中容易形成Ga空位 (即Ga空位浓度较高 ) ,而此时 ,黄光辐射强度单调递增证明 。

The stoichiometry of undoped-GaN layers grown by MOCVD on SiC substrate was determined using X-ray photoelectron spectroscopy(XPS),while the optical properties were measured by photoluminescence(PL).The results indicate that as the Ga atom concentration in GaN layers decreases, the Ga vacancy concentration and peak-intensity of yellow-band increase gradually, this phenomenon can be explained as follows, Ga vacancies are formed easily in the N-rich GaN films and involved in the yellow-band luminescence.