skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Improved InGaN LED System Efficacy and Cost via Droop Reduction

Abstract

Efficiency droop is a non-thermal process intrinsic to indium gallium nitride light emitting diodes (LEDs) in which the external quantum efficiency (EQE) decreases with increasing drive current density. Mitigating droop would allow one to reduce the size of LEDs driven at a given current or to drive LEDs of given size at higher current while maintaining high efficiencies. In other words, droop mitigation can lead to significant gains in light output per dollar and/or light output per watt of input power. This project set an EQE improvement goal at high drive current density which was to be attained by improving the LED active region design and growth process following a droop mitigation strategy. The interactions between LED active region design parameters and efficiency droop were studied by modeling and experiments. The crystal defects that tend to form in more complex LED designs intended to mitigate droop were studied with advanced characterization methods that provided insight into the structural and electronic properties of the material. This insight was applied to improve the epitaxy process both in terms of active region design and optimization of growth parameters. The final project goals were achieved on schedule and an epitaxy process leading to LEDsmore » with EQE exceeding the project target was demonstrated.« less

Authors:
 [1]
  1. Lumileds LLC, San Jose, CA (United States)
Publication Date:
Research Org.:
Lumileds LLC, San Jose, CA (United States); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Brookhaven National Laboratory (BNL), Upton, NY (United States); Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Building Technologies Office (EE-5B)
OSTI Identifier:
1410608
Report Number(s):
DOE-LL-0007136-3
DOE Contract Number:  
EE0007136
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION

Citation Formats

Wildeson, Isaac. Improved InGaN LED System Efficacy and Cost via Droop Reduction. United States: N. p., 2017. Web. doi:10.2172/1410608.
Wildeson, Isaac. Improved InGaN LED System Efficacy and Cost via Droop Reduction. United States. doi:10.2172/1410608.
Wildeson, Isaac. Wed . "Improved InGaN LED System Efficacy and Cost via Droop Reduction". United States. doi:10.2172/1410608. https://www.osti.gov/servlets/purl/1410608.
@article{osti_1410608,
title = {Improved InGaN LED System Efficacy and Cost via Droop Reduction},
author = {Wildeson, Isaac},
abstractNote = {Efficiency droop is a non-thermal process intrinsic to indium gallium nitride light emitting diodes (LEDs) in which the external quantum efficiency (EQE) decreases with increasing drive current density. Mitigating droop would allow one to reduce the size of LEDs driven at a given current or to drive LEDs of given size at higher current while maintaining high efficiencies. In other words, droop mitigation can lead to significant gains in light output per dollar and/or light output per watt of input power. This project set an EQE improvement goal at high drive current density which was to be attained by improving the LED active region design and growth process following a droop mitigation strategy. The interactions between LED active region design parameters and efficiency droop were studied by modeling and experiments. The crystal defects that tend to form in more complex LED designs intended to mitigate droop were studied with advanced characterization methods that provided insight into the structural and electronic properties of the material. This insight was applied to improve the epitaxy process both in terms of active region design and optimization of growth parameters. The final project goals were achieved on schedule and an epitaxy process leading to LEDs with EQE exceeding the project target was demonstrated.},
doi = {10.2172/1410608},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Nov 29 00:00:00 EST 2017},
month = {Wed Nov 29 00:00:00 EST 2017}
}

Technical Report:

Save / Share: