Thickness dependent optical properties of sputtered Bi2Se3 films on mica. (2022)

• Record Type: Journal Article
• Authors: Gautam, S.; Singh, Bheem; Aggarwal, V.; Senthil Kumar, M.; Singh, V.N.; Singh, S.P.; Kushvaha, S.S.
• Is Part Of: Materials today. Volume 64:Part 5(2022)
• Page Start: 1725
• Page End: 1731
• Publication Date: 2022
• Subjects: Bi2Se3 thin film -- Optical properties -- Magnetron sputtering -- X-ray diffraction -- Raman spectroscopy -- Field emission scanning electron microscopy -- Atomic force microscopy; Materials science -- Congresses -- Periodicals; 620.1
• DOI: 10.1016/j.matpr.2022.05.514
• Languages: English
• ISSNs: 2214-7853

Abstract

Abstract: The Bi2 Se3 thin films of different thicknesses (100, 200 and 400 nm) were deposited on mica substrates by magnetron sputtering technique and their structural and optical properties have been studied. The X-ray diffraction analysis revealed the crystalline nature of Bi2 Se3 films with preferred orientation along the c-axis. The presence of three well-pronounced Raman modes i.e. A1 1g, E2g, and A2 1g confirms the formation of pure Bi2 Se3 compound on mica substrates. The field emission scanning electron microscopy and elemental analysis measurements showed the growth of Bi2 Se3 film with varying grain sizes with thickness while maintaining the stoichiometric ratio of 2:3 of Bi and Se. Surface roughness was analysed using atomic force microscopy and it revealed that the roughness increases from 2.16 to 28.3 nm when the film thickness increases from 100 to 400 nm. The optical bandgap analysed with broadband absorption spectroscopy showed a decrease in bandgap from 1.3 to 1.08 eV with increasing film thickness. The sputtered Bi2 Se3 films on mica possess good crystalline and structural quality with tunable bandgap that can be used for futuristic optoelectronic applications.