Micro-photoluminescence analysis of semi- and non-polar nitrides: local efficiency and transport

采用显微光致发光实验技术，在微观尺度上研究了半极性和非极性InGaN量子威尔斯（QW）的光学性质，特别是晶体取向对亚微米光致发光、电致发光和光电流涨落的影响。这些空间分辨的局部测量将与内部量子效率（IQE）和时间分辨电致发光的全球测量进行比较，以研究不同取向的InGaN量子阱中限制量子效率的机制。我们最近证明，“飞行时间”技术允许的InGaN量子阱的平面内的载流子输运的定量测量。该方法将用于测量压电场对半极性和非极性量子阱中载流子漂移和扩散的影响。将解决由于各向异性载流子迁移率和压电场的平面内分量而在半或非极性平面中的各向异性载流子传输（即漂移）的问题。在器件层面上，我们将继续测量和半极性激光二极管的光学增益，波导和动态特性的模拟。

The experimental technique of micro-photoluminescence is used to study the optical properties of semi- and non-polar InGaN quantum wells (QWs) on a microscopic scale, in particular the influence of crystal orientation on sub-micrometer fluctuation of photoluminescence, electroluminescence, and photocurrent. These spatially resolved local measurements will be compared with global measurements of internal quantum efficiency (IQE) and time-resolved electroluminescence to investigate the mechanisms limiting quantum efficiency in InGaN QWs of different orientation. We recently demonstrated that the “time-of-flight” technique allows a quantitative measurement of carrier transport within the plane of the InGaN QW. This method will be used to measure the impact of the piezoelectric field on carrier drift and diffusion in semi- and non-polar QWs. The question of anisotropic carrier transport, i.e. drift, in the semi- or non-polar plane due to anisotropic carrier mobility and an in-plane component of the piezoelectric field will be addressed. On the device level we will continue with measurement and simulation of optical gain, waveguiding, and dynamic properties of semipolar laser diodes.