Photoluminescence of InGaN/GaN and AlGaN/GaN multiple quantum well structures : Role of depletion fields and polarization fields

• We report on low temperature photoluminescence (PL) in InxGa1-xN multiple quantum wells (MQWs) with x in the range 0.1 and highly Si doped barriers of In0.01Ga0.99N. The MQW was placed either in the near surface depletion field or at the n-side depletion field of a pn-junction. At low temperatures the PL and electroluminescence (EL) spectra are quite different at no, low, or reverse bias, the PL appearing at higher energy. At high forward bias a spectral component at the EL position appears in PL. This proves a strong influence of the depletion field on the optical spectra. Preliminary results are also reported for Al0.07Ga0.93N/GaN structures, with near surface MQWs with 5 QWs, both Si-doped and nominally undoped. These structures show clear spectral features related to nonequivalent QWs in a graded depletion field.

Keyword

78.55.Cr; 78.60.Fi; 78.67.De

TECHNOLOGY

TEKNIKVETENSKAP

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art (subject category)