Chemical etching of dislocations in GaSe

Abstract

An etch-pit method has been developed for revealing non-basal dislocations in GaSe single crystal. Shallow background pits, probably nucleated at defects such as vacancies and vacancy clusters, are observed following exposure of the surface to water vapour. The morphology of the etch figures and the variation in etching rates along the primary basal directions are discussed. A tendency for cleavage steps to run in <1010> directions is probably a result of the ionic contribution to the intralayer bonding.