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Comparative Study on Nonradiative Recombination Centers in Proton Irradiated InAs/GaAs Quantum Dot Structure by Two Wavelength Excited PhotoluminescenceComparative Study on Nonradiative Recombination Centers in Proton Irradiated InAs/GaAs Quantum Dot Structure by Two Wavelength Excited Photoluminescence |
"/D. Haque, M./"D. Haque, M. ,
"/Kamata, N./"Kamata, N. ,
"/Sato, Shinichiro/"Sato, Shinichiro ,
"/M. Hubbard, S./"M. Hubbard, S.
内容記述
Comparative study on nonradiative recombination (NRR) centers in InAs/GaAs quantum dot (QD) structure generated by 3 MeV proton irradiation is performed by two wavelength excited photoluminescence (TWEPL). The above-gap excitation (AGE) source of 2.33 eV or 1.26 eV is used to excite GaAs host material or InAs QDs, respectively. The QD PL intensity decreased after irradiation of below-gap excitation (BGE) of 0.75 eV over AGE, indicating a pair of NRR centers activated. The proton irradiation at fluence of 7×1011cm-2 reduces the NRR density, while that of 4×1012cm-2 increases it. Defect formation, carrier injection and their fluence dependence explain experimental results.
