scholarly journals Understanding the Luminescence Characteristics of Ultraviolet InGaN/AlGaN Multiple Quantum Wells with Different In Gradients

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1390
Author(s):  
Jie Zhang ◽  
Wei Liu ◽  
Shuyuan Zhang

The electroluminescence (EL) properties of InGaN/AlGaN ultraviolet light-emitting multiple quantum wells (MQWs) with identical average In content but different In gradients (In content increases linearly, along the growth direction) are investigated numerically. It is found that the luminescence efficiency is improved, and the EL spectral peak wavelength becomes longer for the MQW sample with a larger In gradient. Since the influence of In gradient is different for the conduction and valence bands in InGaN layers, the distribution of electrons and holes in QWs may be changed, leading to a redshift of EL spectra. In particular, when the In gradient increases, the overlap integral of electron-hole wavefunction in InGaN QWs increases, resulting in a higher radiative recombination rate and an enhanced EL intensity.

2019 ◽  
Vol 790 ◽  
pp. 197-202 ◽  
Author(s):  
Xiaowei Wang ◽  
Feng Liang ◽  
Degang Zhao ◽  
Desheng Jiang ◽  
Zongshun Liu ◽  
...  

2008 ◽  
Vol 1 ◽  
pp. 021101 ◽  
Author(s):  
Lai Wang ◽  
Jiaxing Wang ◽  
Hongtao Li ◽  
Guangyi Xi ◽  
Yang Jiang ◽  
...  

2002 ◽  
Vol 722 ◽  
Author(s):  
Mee-Yi Ryu ◽  
C. Q. Chen ◽  
E. Kuokstis ◽  
J. W. Yang ◽  
G. Simin ◽  
...  

AbstractWe present the results on investigation and analysis of photoluminescence (PL) dynamics of quaternary AlInGaN epilayers and AlInGaN/AlInGaN multiple quantum wells (MQWs) grown by a novel pulsed metalorganic chemical vapor deposition (PMOCVD). The emission peaks in both AlInGaN epilayers and MQWs show a blueshift with increasing excitation power density. The PL emission of quaternary samples is attributed to recombination of carriers/excitons localized at band-tail states. The PL decay time increases with decreasing emission photon energy, which is a characteristic of localized carrier/exciton recombination due to alloy disorder. The obtained properties of AlInGaN materials grown by a PMOCVD are similar to those of InGaN. This indicates that the AlInGaN system is promising for ultraviolet applications such as the InGaN system for blue light emitting diode and laser diode applications.


2018 ◽  
Vol 7 (3) ◽  
pp. 1801575 ◽  
Author(s):  
Maotao Yu ◽  
Chang Yi ◽  
Nana Wang ◽  
Liangdong Zhang ◽  
Renmeng Zou ◽  
...  

2014 ◽  
Vol 115 (8) ◽  
pp. 083112 ◽  
Author(s):  
Zhi Li ◽  
Junjie Kang ◽  
Bo Wei Wang ◽  
Hongjian Li ◽  
Yu Hsiang Weng ◽  
...  

2015 ◽  
Vol 23 (7) ◽  
pp. A337 ◽  
Author(s):  
Hung-Ming Chang ◽  
Wei-Chih Lai ◽  
Wei-Shou Chen ◽  
Shoou-Jinn Chang

Author(s):  
A. E. Yunovich ◽  
V. E. Kudryashov ◽  
A. N. Turkin ◽  
A. Kovalev ◽  
F. Manyakhin

Luminescence spectra of Light Emitting Diodes (LEDs) with Multiple Quantum Wells (MQWs) were studied at currents J = 0.15 μA - 150 mA. A high quantum efficiency at low J is caused by a low probability of the tunnel current J (which is maximum at Jm ≈ 0.5-1.0 mA). J(V) curves were measured in the range J= 10−12-10−1 A; at J > 10−3A they may be approximated by a sum of four parts: V= φk+ mkT·[ln(J/J0)+(J/J1)0.5] + J·Rs. The part V ~ (J/J1)0.5is the evidence of a double-injection into i-layers near MQWs. Their presence is confirmed by capacitance measurements. An overflow of carriers through the MQW causes a lower quantum efficiency at high J. A model of a 2D-density of states with exponential tails fits the spectra. The value of T in the active layer was estimated. A new band was detected at high J; it can be caused by non-uniformity of In content in MQWs.


Sign in / Sign up

Export Citation Format

Share Document