Defect assisted nonlinear absorption and optical limiting in amorphous TlGaS2(1-x)Se2(x) (0 <= x <= 1) thin films

Date

2022-01-01

Author

Ünlü, Bekir Asilcan
Karatay, Ahmet
Yildiz, Elif Akhuseyin
Dincbay, Turkan
Ünver, Hüseyin
Hasanlı, Nızamı
ELMALI, Ayhan

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

207
views

0
downloads

In an attempt to investigate the effect of band gap energy and defect states on nonlinear absorption, 80 nm thick amorphous TlGaS2(1-x)Se2(x) thin films with different compositions (0 <= x <= 1) were deposited by vacuum evaporation method. Band gap energies and Urbach energies were obtained from linear absorption spectra. The change in composition led to 0.24 eV increase in band gap energy and 0.32 eV increase in Urbach energy. A theoretical model incorporating one photon absorption, two photon absorption, free carrier absorption and saturation of each absorption process was applied to derive the transmittance in open aperture Z-scan data. The values of nonlinear absorption coefficient and saturation intensity threshold were obtained from the model and two different nonlinear absorption coefficient variation behaviors were observed with increasing Se composition (x) in amorphous thin films based on the opposite contributions of decreasing band gap energies and decreasing Urbach energies on nonlinear absorption.

URI

https://hdl.handle.net/11511/94479

Journal

JOURNAL OF LUMINESCENCE

DOI

https://doi.org/10.1016/j.jlumin.2021.118540

Collections

Department of Physics, Article

Suggestions

OpenMETU
Core

Dielectric and Thermal Effects on the Optical Properties of Natural Dyes: A Case Study on Solvated Cyanin Malcıoğlu, Osman Barış; Gebauer, Ralph; Varsano, Daniele; Baroni, Stefano (2011-10-05) The optical properties of the flavylium state of the cyanin dye are simulated numerically by combining Car-Parrinello molecular dynamics and linear-response time-dependent density functional theory calculations. The spectrum of the dye calculated in the gas phase is characterized by two peaks in the yellow and in the blue (green and violet), using a GGA-PBE (hybrid-B3LYP) DFT functional, which would bring about a greenish (bright orange) color incompatible with the dark purple hue observed in nature. Descri...
Pulse phase resolved x-ray spectroscopy of four accretion powered millisecond pulsars Çolak, Sıdıka Merve; Baykal, Altan; Department of Physics (2014) In this thesis, pulse phase resolved X-ray spectroscopy of four accretion powered millisecond pulsars which are IGR J00291+5934 , IGR J17498-2921 , XTE J0929-314 and XTE J1807-294 will be presented. Phase dependent changes during their outbursts will be checked for possible correlations of spectral parameters such as photon index and blackbody temperature with rotation phase using archive of Rossi X-ray Timing Explorer (RXTE) observations. In the analysis of IGR J17498-2921 in 2011 outburst , positive corre...
Optical absorption of a quantum well with an adjustable asymmetry Yildirim, H.; Tomak, Mehmet (Springer Science and Business Media LLC, 2006-04-01) The effects of asymmetry and the electric field on the electronic subbands and the nonlinear intersubband optical absorption of GaAs quantum wells represented by a Poschl-Teller confining potential are studied. The potential itself can be made asymmetric through a correct choice of its parameter set and this adjustable asymmetry is important for optimizing the absorption. In that way optimal cases can be created. We calculate the modified wave functions and electronic subbands variationally. The linear and ...
Frequency Selective Characteristics of a Plasma Layer with Sinusoidally Varying Electron Density Profile GÜREL, ÇİĞDEM SEÇKİN; Oencue, Emrah (Springer Science and Business Media LLC, 2009-06-01) In this study reflection, absorbtion and transmission characteristics of a plasma layer having sinusoidally varying electron number density are analysed. In the analysis, plasma layer is divided into thin subslabs with constant electron number densities. The general frequency selective behavior of the plasma is investigated by varying the plasma parameters, external magnetic field excitation and sinusoidal electron distribution in order to be used in recent plasma applications.
Temporary and permanent changes to the defect equilibrium due to ultraviolet exposure: Surface and bulk effects on ZnO nanostructures Vempati, Sesha; Ozcan, Sefika; UYAR, Tamer (2018-11-01) We report on the influence of prolonged exposure of above band gap illumination (UV) on the surface electronic structure (core and valence band) and bulk defect equilibrium of ZnO nanorods. We investigated two samples (ZnO1 and ZnO2) of mutually contrasting surface electronic structure as well as photoluminescence responses. The changes due to the above gap exposure were juxtaposed of as-prepared, UV-treated and healed samples. As prepared samples consist of CC, COC and COOH groups at the surface. The intri...

Citation Formats

B. A. Ünlü et al., “Defect assisted nonlinear absorption and optical limiting in amorphous TlGaS2(1-x)Se2(x) (0 <= x <= 1) thin films,” JOURNAL OF LUMINESCENCE, vol. 241, pp. 0–0, 2022, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/94479.