Inversion of the impurity conductivity sign in As$_2$Se$_3$:Bi films deposited by two different methods

It is demonstrated that As$_2$Se$_3$:Bi$_x$ films deposited by thermal evaporation have $p$-type impurity conductivity, whereas films of the same composition, produced by ion-plasma cosputtering in vacuum exhibit $n$-type impurity conductivity. On the basis of these results, a new method is suggested for the fabrication of $p$–$n$ homojunctions in film structures made of chalcogenide glassy semiconductors doped with bismuth in various ways.