Bipolar Transport and Bipolar Photoconductivity in Amorphous Films Containing Arsenic Chalcogenide Vitreous Semiconductors

Comparison of atomic structures and electronic properties of amorphous AsSe films

“…ChGS films of composition As x Se 1−x (x = 0.2, 0.4, 0.5, 0.6 and 0.7) were prepared by thermal evaporation in a vacuum and rf ion-plasma sputtering. The preparation parameters were selected so as to produce amorphous films with a composition corresponding to that of the starting ChGS and having the maximum possible carrier drift mobility [12,14].…”

“…We studied nonequilibrium processes in amorphous films of the As-Se system, prepared by rf sputtering (RF films), and observed effects markedly different from those in films grown by thermal evaporation in a vacuum (TE films) [12][13][14]. It was found that in RF As 2 Se 3 films the drift mobilities of holes and electrons are practically the same (∼ 10 −5 cm 2 V −1 s −1 ) at E = 10 5 Vcm −1 and T = 300 K, with both bipolar transport of carriers and bipolar photoconduction taking place.…”

Differences in local structure between amorphous As Se films prepared by different methods

“…It has been established accurately enough that the structure and electronic properties of ChGS are governed by the conditions of their preparation [4][5][6][7][8][9][10]. For example, we have shown that changing the preparation conditions of amorphous ChGS films of the As-Se system by using different preparation methods (thermal evaporation in a vacuum (TE method) and RF ion-plasma sputtering (RF method)) strongly affects their main electronic parameters [6][7][8][9][10].…”

“…It has been established accurately enough that the structure and electronic properties of ChGS are governed by the conditions of their preparation [4][5][6][7][8][9][10]. For example, we have shown that changing the preparation conditions of amorphous ChGS films of the As-Se system by using different preparation methods (thermal evaporation in a vacuum (TE method) and RF ion-plasma sputtering (RF method)) strongly affects their main electronic parameters [6][7][8][9][10]. The carrier drift mobility and photoconductivity undergo the most pronounced changes, and the extent to which these changes occur becomes greater when the concentration of arsenic in the films grows with respect to the stoichiometric component ratio [6][7][8].…”

“…For example, we have shown that changing the preparation conditions of amorphous ChGS films of the As-Se system by using different preparation methods (thermal evaporation in a vacuum (TE method) and RF ion-plasma sputtering (RF method)) strongly affects their main electronic parameters [6][7][8][9][10]. The carrier drift mobility and photoconductivity undergo the most pronounced changes, and the extent to which these changes occur becomes greater when the concentration of arsenic in the films grows with respect to the stoichiometric component ratio [6][7][8]. Studying the atomic structure of amorphous TE and RF films by the x-ray diffraction method showed that their structures vary [9,10].…”