Annealing Induced Morphology Evolution and Phase Transition in SnOx Thin Films Grown by E-Beam Evaporation Method

In the present work, we demonstrate the growth of tin oxide (SnOx) thin films using electron beam evaporation method to study the phase transition from stannous oxide (SnO) to stannic oxide (SnO2) by varying annealing temperature (i.e., from 300 to 700 degrees C). Annealing induced morphology evolution and structural modifications stimulate the process of phase-transformation, which is primarily discussed by divided the entire temperature range into two-regimes. Regime-A (from 300 to 400 degrees C) consists of tetragonal alpha-SnO dominated phase, regime-B (from 600 to 700 degrees C) exhibits orthorhombic pure SnO2 phase. However, these regimes are being separated by an interface conferring a mixed-phase of tin oxides at an annealing temperature similar to 500 degrees C. This temperature dependent phase-inversion is adequately controlled by tuning the morphological, structural and optical properties of SnOx thin films to develop homo/heterostructures for various photovoltaic and optoelectronic applications.