B.V.Pavlyk, B.Z.Cybulyak, Ya.M.Goryn', I.V.Kozak
Received May 22, 1998
The effect of electron emission from basal S (000bar1) and Cd (0001) faces of CdS crystals when being cooled
down to the liquid nitrogen temperature has been revealed. Anomalous
temperature relationships of the surface conductivity of those faces
have been studied both in high-resistance (ne<<108 cm-3)
and low-resistance (n~1014 cm-3) crystals.
The correlation of results obtained prior to and after the heat treatment
of samples allowed to propose a mechanism of the conductive layer
formation and electron emission in the course of cooling. The interstitial
excess Cd is supposed to be displaced towards the (0001) crystal
face in the band bending field. Metastable defects are formed therewith
in the crystal near-surface layer and re-built as the temperature
lowers forming the low-resistance conductive layer. The crystal pyrofield
stimulates the emission of free electrons into vacuum without preceding
excitation.