SnTexSe1-x Alloy: An Effective Alternative to SnSe Nano-crystalline Thin Films for Optoelectronic Applications

As prepared by fusion, SnTexSe1-x (x=0.68) alloy is found to possess mixed phases of hexagonal Te and orthorhombic SnSe. The deposited films of this alloy demonstrate incongruent evaporation of the constituents. Reductions in c-parameter and strain along the z-axis in lattices of SnSe and Te constituents have been observed in these films at 353K. These deviations in the structure of SnTexSe1-x films make it superior to SnSe for various optoelectronic applications. The absorption coefficient of SnTexSe1-x films is higher than SnSe, and its bandgap attains a value of 0.93eV. Further, resistivity value of SnTexSe1-x (approximate to 6.12x10(-2)cm) is lower and carrier concentration (approximate to 1.31x10(19)cm(-3)) is higher than SnSe, whereas its mobility value (approximate to 25.8cm(2)/Vs) matches SnSe and similar materials. The surface quality of SnTexSe1-x improves and number of crystallites increases. The interface of p-SnTexSe1-x with Ag metal forms a Schottky diode. The current-voltage (I-V) behaviour of Ag/p-SnTexSe1-x Schottky diodes is analysed and diode parameters are determined by using thermionic emission and diffusion (TED) current transport mechanism.