Growth of γ- In2Se3 monolayer from multifaceted InxSey thin films via annealing and study of its physical properties

The dynamics of changing phases of InxSey thin film alloy grown on annealing of the SELD films were analyzed. The thin film samples provide mixed phases of gamma-In2Se3, In4Se3, and InSe at the annealing temperatures of 523 K to 623 K and attain a single phase at 673 K. The presence of strong gamma-In2Se3 phase at 673 K was supported by the vibrational spectra. The films are homogeneous throughout, without cracks well cover the entire glass substrate. The crystallites are densely packed, irregular shaped, and complex structured. The bandgap (E-g) varies from 1.92 eV to 2.39 eV; refractive index (n) from 2.75 to 2.55 while the absorption coefficient (alpha) values limit within 2 x 10(4) to 1.5 x 10(5) cm(-1). This mobility (mu) of the films increases from 871 to 1413 cm(2)/V-s with changing temperature, the change is attributed to the growth of gamma-In2Se3 crystallites. The bandgap tuning, high absorption coefficient, and mobility values exhibited by the films make these suitable for use as buffer layers in the solar cell structure. The undertaken In2Se3 semiconductor, among many other applications, is a candidate to replace CdS in solar cells.