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Thermally enhanced blue light-emitting diode.
- Source :
- Applied Physics Letters; 9/21/2015, Vol. 107 Issue 12, p1-5, 5p, 1 Diagram, 1 Chart, 4 Graphs
- Publication Year :
- 2015
-
Abstract
- We investigate thermoelectric pumping in wide-bandgap GaN based light-emitting diodes (LEDs) to take advantage of high junction temperature rather than avoiding the problem of temperatureinduced efficiency droop through external cooling. We experimentally demonstrate a thermally enhanced 450 nm GaN LED, in which nearly fourfold light output power is achieved at 615K (compared to 295K room temperature operation), with nearly no reduction in the wall-plug efficiency (i.e., electrical-optical energy conversion efficiency) at bias V < hw=q. The LED is shown to work in a mode similar to a thermodynamic heat engine operating with charged carriers pumped into the active region by a combination of electrical work and Peltier heat (phonons) drawn from the lattice. In this optimal operating regime at 615 K, the LED injection current (3.26 A/cm²) is of similar magnitude to the operating point of common high power GaN based LEDs (5-35 A/cm²). This result suggests the possibility of removing bulky heat sinks in current high power LED products thus realizing a significant cost reduction for solid-state lighting. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00036951
- Volume :
- 107
- Issue :
- 12
- Database :
- Complementary Index
- Journal :
- Applied Physics Letters
- Publication Type :
- Academic Journal
- Accession number :
- 109971508
- Full Text :
- https://doi.org/10.1063/1.4931365