Measurement of flicker noise as a diagnostic tool for hot-electron degradation in GaN-based leds

W. K. Fong, K. K. Leung, H. F. Lui, Ping Kong Alexander Wai, C. Surya, Z. Chen, C. B. Cao

Research output: Journal article publicationJournal articleAcademic researchpeer-review


Hot-electron stressing on GaN-based light emitting diodes (LEDs) has been performed using a do stressing current. Detailed characterizations on the degradations in the optoelectronic and low-frequency noise properties of the devices have been conducted. Experimental results on I-V, electroluminescence (EL) and the integrated light output of the devices exhibit significant degradations with the stress time. Investigations on the low-frequency excess noise of the devices show that the degradations of the device properties arise from the generation of interface states at the In-GaN/GaN heterointerface due to hot-electron stressing. Over two orders of magnitude increase in the current noise power spectral density, SI(f), is typically observed prior to the failure of the devices. Furthermore, it is shown that the initial rate of increase in SI(f) resulting from a dc current stress time of 48 hours is strongly correlated to the lifetimes of the devices demonstrating that flicker noise measurement can be used as a diagnostic tool for hot-electron hardness of the device.
Original languageEnglish
JournalFluctuation and Noise Letters
Issue number4
Publication statusPublished - 1 Dec 2007


  • Device reliability
  • GaN LEDs
  • Low-frequency noise

ASJC Scopus subject areas

  • Mathematics(all)
  • Physics and Astronomy(all)


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