Investigation of amorphous-crystalline transformation induced optical and electronic properties change in annealed As50Se50 thin films

Sahoo, D and Priyadarshini, P and Dandela, R and Alagarasan, D and Ganesan, R and Varadharajaperumal, S and Naik, R (2021) Investigation of amorphous-crystalline transformation induced optical and electronic properties change in annealed As50Se50 thin films. In: Optical and Quantum Electronics, 53 (4).

PDF opt_qua_ele_53-04_2021.pdf - Published Version Restricted to Registered users only Download (2MB) | Request a copy

Abstract

The present work reports the amorphous-crystalline phase transformation in thermally evaporated As50Se50 thin films upon annealing at below Tg (423 K) and above Tg (523 K). The structural transition was probed by XRD, Raman and X-ray photoelectron spectroscopy. The composition and surface morphology were probed by EDS and FESEM techniques. The transmittance and reflectance spectra over the wavelength range 500 nm�1200 nm were used to deduce the optical parameters. The various optical parameters of the as-prepared and annealed As50Se50 thin films were estimated and discussed in terms of density of defect states and disorders. The indirect optical energy gap decreased for the 423 K annealed film and abruptly increased for 523 K annealed film as compared to the as-prepared film. The Swanepoel envelope method, WDD model, and Sellemeire postulates were employed for the analysis of refractive index, static refractive index, oscillator energy, dispersion energy, oscillator wavelength and dielectric constant. The changes in the linear and nonlinear properties showed opposite behavior for the two annealed films. The non-linear refractive index and 3rd order susceptibility were found to be increased for 423 K annealed film and decreased for the 523 K annealed film. The optical as well as the electrical conductivity changed with annealing and the electrical susceptibility increased for 523 K annealed film. The tunable optical properties can be applied for several optoelectronic applications. Graphical abstract: The amorphous to crystalline structural transformation occurred at annealing above Tg. The 3rd order susceptibility was found to be more at 423 K annealing and less at 523 K annealing. Figure not available: see fulltext. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.

Item Type:	Journal Article
Publication:	Optical and Quantum Electronics
Publisher:	Springer
Additional Information:	The copyright for this article belongs to Springer
Keywords:	Annealing; Arsenic compounds; Electronic properties; Film preparation; Morphology; Optical variables control; Refractive index; Selenium compounds; Surface morphology; Thin films; X ray photoelectron spectroscopy, Crystalline phase transformation; Crystalline transformation; Electrical conductivity; Optical and electronic properties; Optoelectronic applications; Structural transformation; Transmittance and reflectances; Tunable optical properties, Optical films
Department/Centre:	Division of Interdisciplinary Sciences > Centre for Nano Science and Engineering Division of Physical & Mathematical Sciences > Physics
Date Deposited:	13 Jul 2021 11:39
Last Modified:	13 Jul 2021 11:39
URI:	http://eprints.iisc.ac.in/id/eprint/68806

Actions (login required)

View Item