ELECTRICAL AND OPTICAL-PROPERTIES OF HIGHLY NONSTOICHIOMETRIC GAAS

The studies of transport and optical properties of GaAs implanted with high arsenic doses were performed. As-implanted samples showed hoppin g conductivity and the exponential absorption tail in the near-IR regi on. Both effects were probably caused by the amorphization of implante d layer. Using EPR measurements it was found that arsenic antisite def ect with high local strain field was created during implantation. Anne aling of implanted layers at 600 degrees C led to substantial removal of amorphization, decrease in absorption coefficient and hopping condu ctivity leading to resistive samples. Tile possible model of such beha viour may be similar to the one of suggested for low temperature GaAs layers.