利用MOCVD在Al2O3(0001)衬底上制备InGaN/GaN MQW结构蓝光LED外延片。以400 mW中心波长405 nm半导体激光器作为激发光源, 采用自主搭建的100～330 K低温PL谱测量装置, 以及350～610 K高温PL测量装置, 测量不同温度下PL谱。通过Gaussian分峰拟合研究了InGaN/GaN MQW主发光峰、声子伴线峰、n-GaN黄带峰峰值能量、相对强度、FWHM在100～610 K范围的温度依赖性。研究结果表明：在100～330 K温度范围内, 外延片主发光峰及其声子伴线峰值能量与FWHM温度依赖性, 分别呈现S与W形变化; 载流子的完全热化分布温度约为150 K, 局域载流子从非热化到热化分布的转变温度为170～190 K; 350～610 K高温范围内, InGaN/GaN MQW主发光峰峰值能量随温度变化满足Varshni经验公式, 可在MOCVD外延生长掺In过程中, 通过特意降温在线测PL谱, 实时推算掺In量, 在线监测外延片生长。以上结果可为外延片的PL发光机理研究、高温在线PL谱测量设备开发、掺In量的实时监测等提供参考。

A blue light LED epitaxial wafer with InGaN/GaN MQW structure was prepared on an Al2O3 (0001) substrate by MOCVD. The 400 mW semiconductor laser with a center wavelength of 405 nm was used as the excitation light source. The PL-spectrum at different temperatures was measured by the self-built 100-330 K low-temperature PL spectrum measurement device and the 350-610 K high-temperature PL measurement device. The peak energy and the relative intensity of InGaN/GaN MQW main luminescence peak, the phonon concomitant peak and the n-GaN yellow band peak, as well as the temperature dependence of the FWHM in the range of 100-610 K were studied by Gaussian peak differentiating and imitating. The results showed that in the temperature range of 100-330 K, the peak energy of the main luminescence peak and the phonon concomitant peak of the epitaxial wafer, as well as the temperature dependence of the FWHM displayed S and W-shaped changes respectively; the complete heating distribution temperature of the carrier was about 150 K; the transition temperature of local carriers from non-heating to heating distribution was 170－190 K; in the high temperature ranged 350－610 K, the changes in peak energy of InGaN/GaN MQW with temperature variation satisfied the Varshni empirical formula. In the In-doped process of MOCVD epitaxial growth, the PL spectrum could be measured by deliberately cooling the temperature; the amount of In-doped was calculated in real time; and the epitaxial wafer growth was monitored online. The above results can be used for the study of PL luminescence mechanism of epitaxial wafers, development of high-temperature online PL spectrum measurement equipment, real-time monitoring of In-doped and so on.