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Semiconductor Physics, Quantum Electronics & Optoelectronics. 2009. V. 12, N 3. P. 276-279.
Peculiarities of neutron irradiation influence
on GaP light-emitting structures
Institute for Nuclear Researches, NAS of Ukraine, 47, prospect Nauky, 03028 Kyiv, Ukraine Abstract. GaP LEDs irradiated by reactor neutrons were studied by optical and electrical
methods. The observed emission intensity degradation is related with two factors:
1) radiation fields that destroy bond excitons and 2) decrease in the free charge carrier
concentration, which is caused by their capture by radiation defects. Study of current-
voltage characteristics at 77 K by highly precession methods has revealed the appearance
of N-shaped negative differential region caused by carrier tunneling onto deep levels in
quantum wells, which might exist in initial and irradiated p-n structures. In some cases,
improvement of current-voltage characteristics after neutron irradiation is observed. An
assumption is made about the radiation-stimulated origin of this effect.
Keywords: GaP LEDs, irradiation, emission degradation, negative resistance,
oscillation.
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