Midgap electron traps in n-type GaAs epitaxial layers grown by the close-spaced vapor transport technique

Abstract

The deep-level transient spectroscopy technique was applied to the study of deep electron traps existing in n-type GaAs epitaxial layers that were prepared by the close-spaced vapor transport technique using three kinds of sources (semi-insulator-undoped, Zn-doped and Si-doped GaAs). Two midgap electron traps labelled ELCS1 and EL2 were observed in all layers regardless of the kind of source used. In addition, the effect of the electric field on the emission rate of ELCS1 is discussed and its identification to ETX2 and EL12 is suggested.