Next Article in Journal
Improving the Performance of ZnS Photocatalyst in Degrading Organic Pollutants by Constructing Composites with Ag2O
Next Article in Special Issue
Shape- and Element-Sensitive Reconstruction of Periodic Nanostructures with Grazing Incidence X-ray Fluorescence Analysis and Machine Learning
Previous Article in Journal
Hollow CoP/FeP4 Heterostructural Nanorods Interwoven by CNT as a Highly Efficient Electrocatalyst for Oxygen Evolution Reactions
Previous Article in Special Issue
Progress in Traceable Nanoscale Capacitance Measurements Using Scanning Microwave Microscopy
 
 
Article

Thermophysical Characterization of Efficiency Droop in GaN-Based Light-Emitting Diodes

1
Department of Electronic Engineering, Chang Gung University, Tao-Yuan City 333, Taiwan
2
Department of Computer Science, National Taipei University of Education, Taipei 106, Taiwan
3
Department of Electronic Engineering, Ming Chi University of Technology, New Taipei City 243, Taiwan
*
Author to whom correspondence should be addressed.
Academic Editors: Petr Klapetek and Iván Mora-Seró
Nanomaterials 2021, 11(6), 1449; https://doi.org/10.3390/nano11061449
Received: 9 April 2021 / Revised: 18 May 2021 / Accepted: 27 May 2021 / Published: 30 May 2021
(This article belongs to the Special Issue Nanometrology)
An efficiency droop in GaN-based light-emitting diodes (LED) was characterized by examining its general thermophysical parameters. An effective suppression of emission degradation afforded by the introduction of InGaN/GaN heterobarrier structures in the active region was attributable to an increase in the capture cross-section ratios. The Debye temperatures and the electron–phonon interaction coupling coefficients were obtained from temperature-dependent current-voltage measurements of InGaN/GaN multiple-quantum-well LEDs over a temperature range from 20 to 300 K. It was found that the Debye temperature of the LEDs was modulated by the InN molar fraction in the heterobarriers. As far as the phonons involved in the electron–phonon scattering process are concerned, the average number of phonons decreases with the Debye temperature, and the electron–phonon interaction coupling coefficients phenomenologically reflect the nonradiative transition rates. We can use the characteristic ratio of the Debye temperature to the coupling coefficient (DCR) to assess the efficiency droop phenomenon. Our investigation showed that DCR is correlated to quantum efficiency (QE). The light emission results exhibited the high and low QEs to be represented by the high and low DCRs associated with low and high injection currents, respectively. The DCR can be envisioned as a thermophysical marker of LED performance, not only for efficiency droop characterization but also for heterodevice structure optimization. View Full-Text
Keywords: efficiency droop; Debye temperature; electron–phonon interaction efficiency droop; Debye temperature; electron–phonon interaction
Show Figures

Figure 1

MDPI and ACS Style

Nee, T.-E.; Wang, J.-C.; Zhong, B.-Y.; Hsiao, J.-J.; Wu, Y.-F. Thermophysical Characterization of Efficiency Droop in GaN-Based Light-Emitting Diodes. Nanomaterials 2021, 11, 1449. https://doi.org/10.3390/nano11061449

AMA Style

Nee T-E, Wang J-C, Zhong B-Y, Hsiao J-J, Wu Y-F. Thermophysical Characterization of Efficiency Droop in GaN-Based Light-Emitting Diodes. Nanomaterials. 2021; 11(6):1449. https://doi.org/10.3390/nano11061449

Chicago/Turabian Style

Nee, Tzer-En, Jen-Cheng Wang, Bo-Yan Zhong, Jui-Ju Hsiao, and Ya-Fen Wu. 2021. "Thermophysical Characterization of Efficiency Droop in GaN-Based Light-Emitting Diodes" Nanomaterials 11, no. 6: 1449. https://doi.org/10.3390/nano11061449

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop