掺杂自诱导增强Si基AlGaN深紫外LED研究

Si基AlGaN深紫外LED具有无污染、体积小、寿命长等优势，在医疗卫生、环境保护和信息技术等领域具有广泛应用前景。当前，Si基AlGaN深紫外LED量子效率低下，主要原因之一在于高Al组分AlGaN材料p型掺杂困难。针对于此，本项目提出通过引入掺杂自诱导电离增强机制提高空穴浓度，增加空穴注入效率，进而解决Si基AlGaN深紫外LED效率低下问题。本项目将研究掺杂自诱导增强受主离化机制，揭示掺杂自诱导结构参数对空穴浓度及迁移率影响规律，探明极化诱导与掺杂自诱导协同作用，掌握掺杂自诱导参数对LED效率影响规律；将利用MOCVD实现Mg周期富集并梯度渐变的掺杂自诱导结构，调控组分渐变梯度和掺杂自诱导结构参数，获得高效掺杂的p-AlGaN生长技术，并基于此制备Si基AlGaN深紫外LED器件。本项目为提升高Al组分p-AlGaN效率提供了新思路，有望推动Si基AlGaN深紫外LED的实用化进程。

The Si-based AlGaN DUV-LEDs have the advantages of pollution-free, portability, long-life time, and thus possess great potential in the fields of public health, environmental protection, information technology. However, the current quantum efficiency of the available Si-based AlGaN DUV-LEDs is extremely low and one of the main reasons is the difficulty of p-type doping in AlGaN materials. In the project, we plan to increase the LED quantum efficiency through improving the p-AlGaN doping efficiency by adopting the "dopant-self-induced ionization enhanced mechanism" to improve the hole concentration and the hole injection efficiency. We will study the physical mechanism of the "dopant-self-induced ionization enhencement", analyse the impact mechanism of the dopant-self-induced doping structure parameters on the hole concentration and mobility, reveal the cooperative enhancement mechanism between the polarization-induced doping and the dopant-self-induced doping methods, and master the influence law of the dopant-self-induced doping structure parameters on LED efficiency. We will apply MOCVD to growth Al-content gradually-changed AlGaN layers on Si substrate with Mg-dopant periodically enriching and gradually decreasing. By controlling the gradients of Al-content changing and the dopant-self-induced doping structure parameters, we will obtain high-efficient p-type AlGaN layer and we will apply the technique to Si-based AlGaN DUV-LED to improve the LED quantum efficiency. The project presented here provides a new approach to realize high-efficient p-AlGaN layer with high Al content, and will probably promote the performance of Si-based AlGaN DUV-LED devices.