Evidence of localization effect on photoelectron transport induced by alloy disorder in nitride semiconductor compounds

Abstract

Near-bandgap photoemission spectroscopy experiments were performed on p-GaN and p-InGaN/GaN photocathodes activated to negative electron affinity. The photoemission quantum yield of the InGaN samples drops by more than one order of magnitude when the temperature is decreased while it remains constant on the GaN sample. This indicates a freezing of photoelectron transport in p-InGaN that we attribute to electron localization in the fluctuating potential induced by the alloy disorder. This interpretation is confirmed by the disappearence at low temperature of the peak in the photoemission spectrum that corresponds to the contribution of the photoelectrons relaxed at the bottom of the InGaN conduction band.

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Cited by in corpus (4)

• Increased light-emission efficiency in disordered InGaN through the correlated reduction of recombination rates
• Optical properties of InGaN quantum wells: accurately modeling the effects of disorder
• Effect of Concentration Fluctuations on Material Properties of Disordered Alloys
• Observation of quasi bound states in open quantum wells of cesiated p-doped GaN surfaces