Time dependent laser irradiation induced structural, linear-nonlinear optical changes in Ag10Te10As20Se60 quaternary film for optoelectronic applications

• Published in: European physical journal plus 2023-07, Vol.138 (7), p.639, Article 639
• Main Authors: Das, S., Parida, A., Alagarasan, D., Naik, R.
• Format: Article
• Language: English
• Subjects: Ablation; Absorption; Absorptivity; Applied and Technical Physics; Arsenic; Atomic; Blue shift; Carrier density; Chalcogenides; Complex Systems; Condensed Matter Physics; Contact angle; Dielectric loss; Electronegativity; Exposure; Glass substrates; Hydrophobicity; Irradiation; Lasers; Mathematical and Computational Physics; Microscopy; Molecular; Morphology; Nonlinear optics; Optical and Plasma Physics; Optical properties; Optoelectronics; Parameters; Photobleaching; Physics; Physics and Astronomy; Plasma frequencies; Refractivity; Regular Article; Semiconductors; Structural stability; Theoretical; Thin films; Time dependence; Wettability
• ISSN: 2190-5444; 2190-5444
• DOI: 10.1140/epjp/s13360-023-04221-9

Chalcogenide materials are unique for their peculiar linear and nonlinear optical properties and are suitable for various optoelectronic applications. External inputs alter multiple parameters of the material. The influence of laser irradiation on chalcogenide thin films brings changes in its structural, morphological, linear, and nonlinear properties for different applications. In the current report, the quaternary Ag 10 Te 10 As 20 Se 60 film was irradiated with 532 nm (2.33 eV) continuous laser for various durations. With the increase in the irradiation time, several changes in the material's structural and other optical properties were studied. The polycrystalline nature of the films remains the same upon irradiation, thus showing structural stability. The increase in laser irradiation exposure time also enhanced the heteropolar bonds in the film. The transparency of the material gradually increased with irradiation time and mostly showed in the infrared range (~ 1900 nm). This enables its application as window material in photodetectors and other infrared devices. The absorption edge of the material exhibits a blue shift, which also leads to an increase in the optical bandgap from 1.732 eV (unirradiated) to 2.010 eV (90 min irradiated). The photobleaching reduces refractive index, Urbach energy with the increase in nonlinear absorption coefficient. The χ (3) value reduced from 2.361 × 10 –10 esu (unirradiated) to 0.177 × 10 –10 esu for the 90 min irradiated film. Simultaneously, the optical electronegativity increased from 1.607 (unirradiated) to 1.729 for the 90 min irradiated film. The dielectric losses, carrier concentration, plasma frequency and nonlinear refractive index were also reduced with higher exposure time. The surface wettability of the films showed hydrophobicity properties and remains the same with laser irradiation. The changes in different parameters with laser irradiation make them good candidates for optoelectronic applications, particularly those exposed repeatedly to laser sources. Graphical abstract The influence of 532 nm laser irradiation on the optical changes of Ag 10 Te 10 As 20 Se 60 quaternary thin films. The irradiation influenced the structural, linear and the nonlinear optical parameters.