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Low-frequency noise sources in as-prepared and aged GaN-based light-emitting diodes.
- Source :
- Journal of Applied Physics; 6/15/2005, Vol. 97 Issue 12, p123714, 7p, 1 Chart, 5 Graphs
- Publication Year :
- 2005
-
Abstract
- The low-frequency noise sources are investigated in as-prepared and aged GaN light-emitting diodes (LEDs). Accelerated aging is performed by thermal (300 h at 240 °C) and electrical forward-bias stressing (20 and 50 mA for 2500 h). At low currents I<I<subscript>RTS</subscript>, where I<subscript>RTS</subscript> is a critical current, the low-frequency noise is dominated by random telegraph signal (RTS) noise on top of the 1/f noise. An explanation is given for the giant relative current jumps ĪI/Iā50% and an expression for I<subscript>RTS</subscript> is derived. The RTS noise in our devices is a less-sensitive diagnostic tool for studying the results of accelerated aging. Two components of the 1/f noise were observed: one is related to the quantum-well junction and the other is due to series resistance noise. The two 1/f spectra have different current dependences. It was found that the junction 1/f noise is not significantly affected by aging. However, a strong increase in series resistance noise, by a factor of 60ā800 compared to unstressed devices, is observed after strong electrical and thermal aging. This high increase goes hand in hand with a relatively small increase in the value of the series resistance (13%ā90%). This makes 1/f noise a very sensitive reliability indicator for GaN LEDs after accelerated aging. We discuss the physical origin of LED degradation. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00218979
- Volume :
- 97
- Issue :
- 12
- Database :
- Complementary Index
- Journal :
- Journal of Applied Physics
- Publication Type :
- Academic Journal
- Accession number :
- 17523173
- Full Text :
- https://doi.org/10.1063/1.1942628