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We demonstrate that the GaAs/AlGaAs nanowires (NWs) ensemble is fabricated into photo-detectors. Current–voltage (I–V) characteristics are measured on GaAs/AlGaAs core–shell ensemble NW photo-detectors at room-temperature before and after 1-MeV proton irradiation with fluences from cm to cm. The degradation of photocurrent suggests that the point defects induced by proton radiation could cause both carrier lifetime and carrier mobility to decrease synchronously. Comparing with a GaAs quantum well, the degradations of light and dark current for the irradiated NWs photo-detector indicate that NWs material is a preferable potential candidate for space applications. [ABSTRACT FROM AUTHOR]

To gain a physical insight into the radiation effect on nanowires (NWs), the time resolved photoluminescence (TRPL) technique is used to investigate the carrier dynamic behaviors in GaAs/AlGaAs core–shell NWs before and after 1-MeV proton irradiation with fluences ranging from cm to cm. It is found that the degradations of spectral peak intensity and minority carrier lifetime show similar trends against irradiation fluence, which is closely related to the displacement defects induced by irradiation. We also find that the proton irradiation-induced defects behave as Shockley–Read–Hall (SRH) recombination center trapping free carriers. Finally, the defect concentration could be estimated through measuring the minority carrier lifetime. [ABSTRACT FROM AUTHOR]