Change in the type of majority carriers in disordered InxSe100-x thin-film alloys

Electrical, optical and physico-chemical properties of disordered InxSe100-x thin films have been investigated for x ranging from 40-65. The films are found to be p-type for composition ranging from 45-60 at % selenium and n-type for compositions below 40 at % selenium. An increase in the conductivity, together with a decrease of the activation energy and of the optical gap, has also been observed when x varies from 40-65. These results have been interpreted through a theory based on the relative percentage evolution of the In-in and Se-Se chemical bonds and, on the other hand, by a percolation theory due to microcrystalline structures and indium filaments. These two models are discussed in reference to other publications.