30 MeV Electron Beam Irradiation Effects on GaAs(1-x)P(x) LEDs (Light Emitting Diodes).
Abstract
LEDs of the ternary alloy GaAs(.7)P(.3), were irradiated with a 30 MeV electron beam. The effects this exposure had on peak wavelength, absolute and relative light output intensities, and current-forward bias characteristics were studied. A simple model of LED current controlling mechanisms is described and a mathematical approach for deriving a descriptive damage-constant is provided. Observed irradiation effects consisted of increased current and decreased light output intensity for a given forward bias voltage and indicate that the devices tested are an order of magnitude softer to electron radiation than results previously reported. Damage constants were calculated: group 9 (2.9 x 10 to the -14th power sq cm/e), group A5 (2.6 x 10 to the -14th power sq cm/e), and group 3 (1.4 x 10 to the -14th power sq cm/e). Shielded and un-shielded devices were compared to determine if the secondary electron production for Bremsstrahlung losses would reduce the total fluence required for degradation. The results of this experiment were inconclusive. A procedure was developed to determine the electron beam current density for use in dose estimations. Electron doses were a factor of three higher when compared to the previous method of calculation. Keywords include: LEDs, GaAS(1-x)P(x), electron beam, Bremsstrahlung losses, electroluminescence, and damage constant.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1985
- Accession Number
- ADA158832
Entities
People
- J. K. Foley
Organizations
- Naval Postgraduate School