Fabrication of high hole density p-type nitride semiconductor film crystal using alternating xrdoping techniques and its applications

高强度紫外激光二极管（UV）和发光二极管（led）在高效照明、生物化学和医疗领域或高密度光存储领域的应用需求日益增加。GaN和iii -氮化物化合物半导体作为实现uv - ld和led的候选材料受到了广泛的关注。然而，由于难以获得高al含量的p型AlGaN，使用氮基材料很难实现高效的深紫外led或ld。本工作的目的是利用交替共掺杂技术实现宽带隙p型AlGaN的高空穴密度，并开发工作波长在250-350 nm之间的高效深紫外led或ld。首先，我们展示了使用交替供气法制造Si/Mg共掺杂GaN外延膜的高空穴密度。通过引入si掺杂浓度，我们在mg掺杂GaN中获得了明显的空穴密度增加。然后，采用交变供气法制备了高铝掺镁的AlGaN。我们利用交替供气法获得了Al含量极高（46-53%）mg掺杂AlGaN的空穴导电性。我们还观察到通过引入Si/Mg共掺杂到AlGaN中可以降低活化能。利用交替气柔法生长的高铝含量（53%）p型AlGaN制备了310 nm波段的深紫外发光二极管（led）。我们已经在波长308-314 nm之间的RT脉冲操作下实现了亚毫瓦的输出功率。

The demands for high-intensity ultraviolet (UV) laser diodes (LDs) and light-emitting diodes (LEDs) are increasing for the application of high-efficiency lighting, biochemical and medical fields or high-density optical storages. GaN and III-nitride compound semiconductors are attracting considerable attention as candidate materials for the realization of UV-LDs and LEDs. However, it is difficult to achieve high-efficiency deep UV-LEDs or LDs using nitride-based materials because of the difficulty in obtaining High-Al-content p-type AlGaN. The purpose of this work is to achieve high-hole-density for wide-bandgap p-type AlGaN using an alternating co-doping technique, and to develop high-efficiency deep UV LEDs or LDs operating in the wavelength between 250-350 nm.First, we have demonstrated high-hole-density for Si/Mg co-doped GaN epitaxial filmes fabricating using alternating gas supply method. We obtained significant increase of hole density by introducing Si-doping concentration in Mg-doped GaN. Then, we fabricated high-Al-content Mg-doped AlGaN using alternating gas supply method. We obtained hole-conductivity for extremely high Al content (46-53%) Mg-doped AlGaN by using the alternating gas supply method. We have also observed the reduction of activation energy by introducing Si/Mg co-doping into AlGaN. We fabricated 310 nm-band InAlGaN-based deep UV light-emitting diodes (LEDs) with high-Al-content (53%) p-type AlGaN grown with the alternating gas supple method. We have achieved sub-milliwatt output power under RT pulsed operation in the wavelength between 308-314 nm.