Electrical and optical properties of amorphous As2Se, films modified by tin (a non-transition metal) and iron (a transition metal) as well as the state of the modifying impurity atoms are investigated. Tin is found electrically inactive in the modified films like in vitreous As2Se3. Iron in the modified films is shown to form donor centers with the ionized and neutral states corresponding to the Fe3+ and Fez + ions, respectively. A conclusion is made that an electrical activity of impurities in the chalcogenide semiconductors modified films results from the chemical nature of modifiers whereas the rf co-sputtering technique provides their high concentration only.a TaKXe COCTORHUe MOAU@HUHpyK)WX IIpUMeCHbIX BTOMOB. YCTaHOBJIeHO, YTO OJIOBO B MOAU@U~UpOBaHHbIX nJIeHKaX 3JIeKTpUSeCKU HeaKTBBHO, KBK € i B CTeKJIOO6pa3HOM As,Se,. XeJIe30 o6pa3ye~ B nJIeHKaX As2Se3 AOHOpHbIe GeHTPbI, UOHK30BaHHOMY COCTOIIHEIK) KOTOpbIX COOTBeTCTByeT UOH Fe3 + , a He8TPaJlbHOMY Fez + . CAeJIaH BbIBOA, YTO 3JIeKTpUYeCKaX BKTUBHOCTb IIpHMeCeg B MOAA@U~UPOBaHHbIX IIJIeHKaX XaJIbKOreHWHbIX nOJIyIIpOBOAHUKOB CBR3aHa C XEMUYeCKO~ npUpOAOfi MOAU@UKaTOpa, a MeTOA BY PaCl' IbIfieHUX 0 6 e c n e~u~a e~ TOJIbKO er0 BbICOKYK) KOHUeHTpaUUEO.modified films is not clearly understood, too.The aim of this work is a comparison of the properties of the typical vitreous semiconductor As$, doped with a non-transition metal (tin) by melting and by the modifying technique, on the one hand, and of the iron modified As,Se, films, on the other hand, as well as the determination of the conductivity mechanism of the iron modified As,Se, films.
ExperimentalBulk As,Se, was doped with tin by alloying As,Se, with metallic tin in evacuated quartz ampoules. The melt has been kept at 950 "C for 4 h under permanent vibrational stirring ') Politekhnicheskaya 26, SU-194021 Leningrad, USSR.