Optical Properties of Silicon-doped InGaN and GaN Layers
- 物理技术－已发表论文 
采用光致发光方法研究了采用金属有机化学气相沉积(MOCVD)在蓝宝石衬底上生长的掺硅InGaN和掺硅GaN材料的光学性质。在室温下,InGaN材料带边峰位置为437.0nm,半高宽为14.3nm;GaN材料带边峰位置为363.4nm,半高宽为9.5nm。进行变温测量发现,随温度的升高,两种材料的发光强度降低,半高宽增大;GaN材料的带边峰值能量位置出现红移现象,与Varshini公式符合较好;InGaN材料的带边峰值能量位置则出现红移 蓝移 红移现象,这与InGaN材料的局域态、热效应以及由于电子 空穴对的形成而造成的无序程度增加有关,对大于140K的峰值能量位置的红移用Varshini公式拟合,符合较好。The optical properties of silicon-doped InGaN and GaN grown on sapphire by MOCVD were investigated by photoluminescence (PL) method. At room temperature, the band-edge peak of InGaN is 437.0 nm and its full width of half-maximum (FWHM) is about 14.3 nm. The band-edge peak and FWHM for GaN are 364.4 nm and 9.5 nm, respectively.The peak energy position, the PL intensity, and the FWHM were studied as functions of temperature. By changing temperature from 20 K to 293 K, it was found that the PL intensity of samples decreases but the FWHM broadens with increasing temperature. Meanwhile, the peak energy position of GaN shows red-shift, which has good agreement with Varshini formula. While InGaN shows red-blue-red-shift with increasing temperature, which is supposed to be related with the localized character of the radiative electron-hole recombination, initial thermalization and an increasing entropy due to the formation of electron-hole pairs.