P-type silicon as hole supplier for nitride-based UVC LEDs
- Title
- P-type silicon as hole supplier for nitride-based UVC LEDs
- Author
- 정예환
- Keywords
- tunneling; single crystal nanomembrane; atomic layer deposition; transfer printing; hole injector; light emitting diodes
- Issue Date
- 2019-02
- Publisher
- IOP PUBLISHING LTD
- Citation
- NEW JOURNAL OF PHYSICS, v. 21, article no. 023011
- Abstract
- The ineffective p-type doping of nitrides using magnesium (Mg), the best available dopant, has limited the development and performance of all III-nitride-based devices, including bipolar junction transistors and light emitting diodes (LEDs). For nitride-based ultraviolet (UV) LEDs, as the Al composition increases for achieving shorter wavelengths (e.g. <280 nm) into the UVC spectral range, the p-type doping issue, which causes very inefficient hole injection, becomes more severe than ever. In this work, we report the detailed study of using p-type Si as a hole supplier for high-Al composition UVC LEDs. We first describe the method of Si/GaN junction formation, where the lattice-mismatch challenge between Si and GaN is overcome by using a 0.5 nm thick Al2O3 layer at the interface. This serves as a physical separation layer between the two materials as well as a passivation, tunneling, and thermal buffer layer. High-resolution transmission electron microscope image illustrates the high-quality interface between Si and GaN. We further detail the hole transport mechanism of the p-p Si/GaN isotype junction through both simulations and experiments. The enhanced hole concentration in the AlGaN/AlN multiple quantum wells (MQWs) due to the use of p-type Si as the hole supplier is verified through comparison with conventional UVC LEDs. Finally, high-performance UVC LEDs made with AlN/AlGaN (Al: 72%) MQWs employing p-type Si as their hole suppliers are demonstrated experimentally to serve as an example of the novel hole injector strategy.
- URI
- https://iopscience.iop.org/article/10.1088/1367-2630/ab0445https://repository.hanyang.ac.kr/handle/20.500.11754/160665
- ISSN
- 1367-2630
- DOI
- 10.1088/1367-2630/ab0445
- Appears in Collections:
- COLLEGE OF ENGINEERING[S](공과대학) > ELECTRONIC ENGINEERING(융합전자공학부) > Articles
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