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  • Impact of doped barriers on the recombination coefficients of c -plane InGaN/GaN single quantum well light-emitting diodes
Title: Impact of doped barriers on the recombination coefficients of c -plane InGaN/GaN single quantum well light-emitting diodes
Differential carrier lifetime measurements were performed on c-plane InGaN/GaN single quantum well (QW) light-emitting diodes (LEDs) of different QW indium compositions as well as with and without doped barriers. Mg-doped p-type and Si-doped n-type barriers close to the QW were used to reduce the net internal electric field in the QW, thereby improving the electron–hole wavefunction overlap on the LEDs. LEDs with doped barriers show short lifetimes and low carrier densities in the active region compared to the reference LEDs. The recombination coefficients in the ABC model were estimated based on the carrier lifetime and quantum efficiency measurements. The improvement in the radiative coefficients in the LEDs with doped barriers coupled with the blueshift of the emission wavelengths indeed indicates an enhancement in wavefunction overlap and a reduction of quantum confined Stark effect as a result of the reduced internal electric field. However, doped barriers also introduce non-radiative recombination centers and thereby increase the Shockley–Read–Hall (SRH) coefficient, although the increment is less for LEDs with high indium composition QWs. As a result, at high indium composition (22%), LEDs with doped barriers outperform the reference LEDs even though the trend is reversed for LEDs with lower indium composition (13.5%). Despite the trade-off of higher SRH coefficients, doped barriers are shown to be effective in reducing the internal electric field and increasing the recombination coefficients.  more » « less
Award ID(s):
1839077
PAR ID:
10439913
Author(s) / Creator(s):
; ; ; ; ;
Publisher / Repository:
American Institute of Physics
Date Published:
Journal Name:
Applied Physics Letters
Volume:
121
Issue:
18
ISSN:
0003-6951
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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