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Details a study which examined the influence of photoexcitation on the hopping conduction in neutron transmutation doping gallium arsenide (GaAs). Discussion of the neutron transmutation doping of GaAs; Measurement of photoconductance; Temperature dependence of photoconductance.

Deals with a study which examined the annealing behavior of photoconductance in semi-insulating gallium arsenide crystals in terms of the electron-irradiation-induced defects. Techniques used in studying point defects; Information on the materials; Peak of photoluminescence emissions.

Presents a study that reported a preliminary evaluation of the uniformity of electrical properties in neutron transmutation doping (NTD) semi-insulating gallium arsenide (GaAs) after annealing. Description of NTD; Limitations of low-level NTD in semi-insulating GaAs; Difference between the resistivities for the samples irradiated at different correlates and the amount of activated impurities in each sample.

In undoped and In-doped semi-insulating GaAs with various dislocation densities, we have found that the quenching phenomenon of photoconductance is enhanced by γ irradiation above 107 rad at room temperature. In particular, this effect is obvious for crystals with dislocation densities of 10–103/cm2. The new stage induced by γ irradiation is found around 100 K and disappears gradually by annealing above 300 °C. The time dependence of photoconductance suggests the existence of the newly introduced state assisting the transition from a normal midgap electron trap (EL20) to a metastable state (EL2*) in the semi-insulating materials. [ABSTRACT FROM AUTHOR]