Semimetal–semiconductor transition with a change in the thickness of a bismuth–antimony alloy thin film
Annotatsiya
The changes in the electrical resistance and the magnetoresistance coefficient have been studied for Bi films and Bi1−x Sbx alloys (x = 0.168) at 4.2 and 300 °K with an increase of thickness L from 4 to 10 μ. It has been established previously that in the region of composition with x > 0.065 which corresponds to the semiconductor spectrum in bulk crystals, in films less than 2μ thick there is a semimetallic state due to the change in the structure of the spectrum under the influence of the film potential. A comparison of the behavior of the resistance and magnetoresistance of bismuth and alloy films in the region of large thicknesses allows one to establish that in Bi0.83Sb0.17 alloy films with L > 7 μ there is a decrease in the carrier concentration which indicates a semimetal-semiconductor transition with increasing film thickness.