CRYSTALLIZATION OF AMORPHOUS INDIUM SELENIDE THIN FILMS

In this paper, we study the crystallization of amorphous indium selenide (InSe) films during heat treatment in an inert atmosphere. The films were obtained by thermal evaporation of bulk stoichiometric InSe crystals under conditions of high vacuum. The film structure was analyzed using Raman spectroscopy and X-ray diffraction analysis, the results of which indicate the initial amorphous phase that transforms into a stoichiometric InSe structure with a hexagonal crystal lattice under heat treatment at 350°C. A feature of the studied films is a significant contrast in the specific electrical resistance between the amorphous and crystalline states. The transition to the crystalline phase is accompanied by a sharp decrease in electrical resistance – by several orders of magnitude, which makes it possible to indirectly determine the crystallization temperature of the films by measuring the temperature dependence of the sample’s resistance. In this work, a sharp change in resistance was found in the region of ~ 140°C, corresponding to the crystallization temperature of the studied samples. The obtained results confirm the possibility of forming a polycrystalline InSe film on large areas, which in turn is important when creating prototypes of optoelectronic devices. Furthermore, in this work, the feasibility of local crystallization of InSe thin films was demonstrated using laser patterning technique.

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