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本文通过变温和变激发强度的光致发光研究了用MOCVD在Al2O3上生长GaN单晶薄膜的带边发射，通过分峰拟合得到A、B、C、D四个谱峰，其中半峰宽分别为13．8meV10.8meV、15.6meV和50meV.A对应自由激子谱区，B、C为两种束缚激子的跃迁，D与氧杂质谱有关．通过实验观察到由于外延层对衬底的压缩应变引起自由激子谱峰向高能方向位移以及高激发密度下由于激子间的相互作用产生峰值能量为3．452eV的谱峰．对我们样品中占主导地位的C峰，分析了激发强度和温度对峰值能量和半宽度的关系，并给出实验和计算的结果．
In this paper, the edge emission of GaN single crystal thin film grown on Al2O3 by MOCVD was studied by photoluminescence with variable temperature and varying excitation intensity. The peak spectra of A, B, C and D were obtained by peak fitting. The half-width Respectively, 13.8meV10.8meV, 15.6meV and 50meV.A correspond to the free exciton spectral region, B and C are the transitions of two bound excitons, and D is related to the oxygen impurity spectrum. It is observed experimentally that due to the compressive strain of the epitaxial layer on the substrate, the shift of free exciton peak to high energy direction and the peak energy of 3.452 eV due to the interaction between excitons under high excitation density are obtained. For the dominant C peak in our sample, the relationship between excitation intensity and temperature on the peak energy and half-width was analyzed and the experimental and computational results were given.