In_xGa_(1-x)N/In_yGa_(1-y)N多量子阱结构发光特性的测量与分析

Characterization and Analysis on the Optical Properties of In_xGa_(1-x)N/In_yGa_(1-y)N Multiple Quantum Well Structures

利用MOCVD方法在蓝宝石衬底上生长了InxGa1-xN/InyGa1-yN多量子阱结构外延层,并用变温光致发光(PL)光谱、选择激发光谱以及激发(PLE)光谱等手段研究了该结构的量子效率、多峰效应的起源以及峰位随温度变化等信息。变温PL光谱的结果表明:在温度从30K变化到300K时,其峰值强度只下降了1.36倍且发光波长发生了蓝移。通过选择激发光谱证明了其发光峰位的独立性。PLE结果表明了GaN和势垒层的Stokes位移很小,但是InxGa1-xN阱层的Stokes位移变化很大。同时,提出了一种可同时获得多个吸收边的数据处理方法。

The InxGa1-xN/InyGa1-yN multiple quantum well structures were grown on sapphire substrate by metal-organic chemical vapor deposition （MOCVD）. The quantum efficiency, multi-emission peaks effects and peak-shift information were observed by temperature dependent photoluminescence （PL） spectra, selective excitation PL spectra and PL excitation spectra. The temperature dependent PL spectra showed that the intensity of the main emission peaks decreased only by a factor of 1.36 and peak position has a blue-shift when temperature increases in 30 -300 K. Selective excitation PL spectra showed that every peak appeared in PL spectra is separate. The PLE result shows a small Stokes shift for GaN and barrier layer while it is larger for the well layers. A fitting method was also suggested to obtain several absorption edges Simultaneously.