Influence of photoexcitation on hopping conduction in neutron-transmutation-doped GaAs

Abstract

The nature of the tunneling-assisted hopping conduction in neutron-transmutation-doped GaAs has been studied under photoexcitation with a photon energy of 1.32 eV. It is found that the dopants activated by annealing around 400 °C provide the electrons to the defect levels originating the hopping conduction even when under photoexcitation. The hopping conduction under photoexcitation is affected by quenching in photoconductance below 120 K concerned with the main electron trap (EL2) and/or the As antisite defect (AsGa) induced by the neutron irradiation. The photoconductance of the samples with a lower radiation damage, AsGa≤1×1018 cm−3, consists of the coexistence of the hopping and band conductions.

Cross section measurements for gallium in the neutron energy range of 13.5 to 14.8MeV

“…The value of n i σ i c in GaAs is estimated to be ∼ 0.16 cm −1 [7], N NTD is determined precisely by the thermal neutron fluence (Φt). So the related reaction cross section is very important in research of neutron transmutation doping.…”

Ion channeling and Raman scattering studies of the lattice disorder and residual strain in neutron irradiated GaN

“…Neutron irradiations were performed using the Kyoto University Reactor [13], which is a light-water-moderated reactor. Samples were irradiated with thermal and fast neutrons at fluxes of 8.15 £ 10 13 and 3.90 £ 10 13 cm 22 s 21 , respectively.…”

Phonon shifts relating to the defect structure in neutron-transmutation-doped semi-insulating GaAs

“…The detailed situation of the neutron irradiation was described in our previous paper. 5 A laser Raman spectrophotometer ͑JASCO NR-1800͒ was employed for a study of Raman scattering. The Raman spectra were taken at room temperature in backscattering and nonbackscattering geometry, using the 514.5-nm line of an Ar ϩ -ion gas laser with a power of 100 mW.…”