Exploring the photoluminescence emission behaviour of vacuum deposited Sb2O3 thin film having randomly oriented thorn like structures

An intense UV-visible photoluminescence of vacuum deposited Sb2O3 thin film surface crowded with randomly oriented thorn like structures have been studied using photoluminescence (PL) spectroscopy. The resulting UV emissions are near band edge (NBE) emissions. All the visible deep level emissions (DLE) are due to oxygen defect states. The thorn like structures is achieved by the inclined arrangement of substrates with respect to the source in the vacuum chamber. Some distorted polygonal shapes also emerge among the randomly oriented thorns giving an impression of a hybrid formation upon annealing. This formation of various structures leads to decreased UV NBE and defect level PL emission. The excitation wavelength dependence of PL emission has also been studied. The optical band gap energy of the film is found to be varying from 3.64 to 3.42 eV on annealing. The prepared films are of Sb2O3 cubic structure with polycrystalline nature as confirmed from XRD results. The emergence of thorn like morphology is clearly demonstrated with the aid of FE-SEM and TEM analyses. EDS verifies the elemental composition of Sb2O3. This paper provides an insight into the influence of confinement directions or film surface morphology on the PL emission intensities and PL emission ranges of Sb2O3.