Strain induced power enhancement of far-UVC LEDs on high temperature annealed AlN templates

被引：20

作者：

Knauer, A. ^{[1
]}

Kolbe, T. ^{[1
]}

Hagedorn, S. ^{[1
]}

Hoepfner, J. ^{[2
]}

Guttmann, M. ^{[1
]}

Cho, H. K. ^{[1
]}

Rass, J. ^{[1
]}

Ruschel, J. ^{[1
]}

Einfeldt, S. ^{[1
]}

Kneissl, M. ^{[1
]}

Weyers, M. ^{[1
]}

机构：

[1] Ferdinand Braun Inst FBH, Gustav Kirchhoff Str 4, D-12489 Berlin, Germany

[2] Tech Univ Berlin, Inst Solid State Phys, Hardenbergstr 36, D-10623 Berlin, Germany

来源：

APPLIED PHYSICS LETTERS | 2023年 / 122卷 / 01期

关键词：

LIGHT-EMITTING DIODE;

D O I：

10.1063/5.0134253

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

High temperature annealed AlN/sapphire templates exhibit a reduced in-plane lattice constant compared to conventional non-annealed AlN/sapphire grown by metalorganic vapor phase epitaxy (MOVPE). This leads to additional lattice mismatch between the template and the AlGaN-based ultraviolet-C light emitting diode (UVC LED) heterostructure grown on these templates. This mismatch introduces additional compressive strain in AlGaN quantum wells resulting in enhanced transverse electric polarization of the quantum well emission at wavelengths below 235 nm compared to layer structures deposited on conventional MOVPE-grown AlN templates, which exhibit mainly transverse magnetic polarized emission. In addition, high temperature annealed AlN/sapphire templates also feature reduced defect densities leading to reduced non-radiative recombination. Based on these two factors, i.e., better outcoupling efficiency of the transverse electric polarized light and an enhanced internal quantum efficiency, the performance characteristic of far-UVC LEDs emitting at 231 nm was further improved with a cw optical output power of 3.5 mW at 150 mA.

引用

页数：6