title: Radiation effects on GaAs/AlGaAs core/shell ensemble nanowires and nanowire infrared photodetectors.
abstract: With the recent advances in nanowire (NW) growth and fabrication, there has been rapid development and application of GaAs NWs in optoelectronics. It is also of importance to study the radiation tolerance of optoelectronic nano-devices for atomic energy and space-based applications. Here, photoluminescence (PL) and time-resolved photoluminescence measurements were carried out on GaAs/AlGaAs core/shell NWs at room temperature before and after 1 MeV proton irradiation with fluences ranging from 1.0 × 1012-3.0 × 1013cm-2. It is found that the GaAs/AlGaAs core/shell NWs with smaller diameter show much less PL degradation compared with the ones with larger diameters. The increased radiation hardness is mainly attributed to the improvement of a room temperature dynamic-annealing mechanism near the surface of the NWs. We also found that the minority carrier lifetime is closely related to both the PL intensity and defect density induced by irradiation. Finally, GaAs/AlGaAs ensemble NW photodetectors operating in the near-infrared spectral regime have been demonstrated. The influence of proton irradiation on light and dark current characteristics also indicates that NW structures are a good potential candidate for radiation harsh-environment applications.
authors.affiliation: National Key Laboratory of Tunable Laser Technology, Harbin Institute of Technology, Harbin 150001, People's Republic of China. Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra 2601, A.C.T., Australia.
authors.forename: Fajun
authors.initials: F
authors.lastname: Li
authors.forename: Ziyuan
authors.initials: Z
authors.lastname: Li
authors.forename: Liying
authors.initials: L
authors.lastname: Tan
authors.forename: Yanping
authors.initials: Y
authors.lastname: Zhou
authors.forename: Jing
authors.initials: J
authors.lastname: Ma
authors.forename: Mykhaylo
authors.initials: M
authors.lastname: Lysevych
authors.forename: Lan
authors.initials: L
authors.lastname: Fu
authors.forename: Hark Hoe
authors.initials: HH
authors.lastname: Tan
authors.forename: Chennupati
authors.initials: C
authors.lastname: Jagadish