Crystals were grown by using the vapour pressure controlled Czochralski method without boric oxide encapsulant. The melt compositions were in situ controlled and the C concentration adjusted. Weakly doped p- and n-type conducting GaAs were studied with respect to their content of native and extrinsic defects. The influence of low B concentrations upon vacancy-type defects investigated by positron annihilation technique and cathodoluminescence were presented. The results were compared with those obtained for conventionally grown material.

Vacancy-Type Defects in Boron-Reduced VCz GaAs Crystals. F.M.Kiessling, P.Rudolph: Journal of Physics and Chemistry of Solids, 2008, 69[2-3], 289-93