Open AccessUV Light-Emitting Diode With Buried Polarization- Induced n-AlGaN/InGaN/p-AlGaN Tunneling Junction
Author(s) -
Yi Lu,
Chuanju Wang,
Victor Paiva De Oliveira,
Zhiyuan Liu,
Xiaohang Li
Publication year - 2021
Publication title -
ieee photonics technology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.81
H-Index - 157
eISSN - 1941-0174
pISSN - 1041-1135
DOI - 10.1109/lpt.2021.3065095
Subject(s) - engineered materials, dielectrics and plasmas , photonics and electrooptics
The polarization-induced electric field in the III-nitride UV light-emitting diode (LED) allows for significant flexibility in device design to address the electron overflow and hole injection issues. The conventional AlGaN-based UV LED with the PIN structure suffers from insufficient carriers especially hole concentration due to the large valence band barrier for hole injection and p-type doping challenge. Our systematic study reveals that the inverse design of the n-type and p-type layer shall build an opposite polarization-induced field to suppress electron overflow as well as simultaneously enhance hole injection. To design this p-side down UV LED and improve the hole injection, we adopt the n-AlGaN/i-InGaN/p-AlGaN buried tunneling junction (BTJ) instead of the bottom p-layer. The tunneling probability and output power of the LED are further investigated by optimizing the composition and thickness of the InGaN layer. Simulation results show that the optimized 3 nm In0.3Ga0.7N tunneling layer could lead to several orders of magnitude enhancement for LED output power. This study is significant for the pursuit of highly efficient UV LEDs.