Laser-induced optical photobleaching in Bi-doped Ge30Se70 amorphous thin films

• Published in: Applied physics. A, Materials science & processing Vol. 126; no. 1
• Main Authors: Aparimita, Adyasha, Naik, R., Sripan, C., Ganesan, R.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 2020; Springer Nature B.V
• Subjects: Applied physics; Bismuth; Characterization and Evaluation of Materials; Chemical composition; Condensed Matter Physics; Emission analysis; Field emission microscopy; Irradiation; Lasers; Machines; Manufacturing; Materials science; Morphology; Nanotechnology; Optical and Electronic Materials; Optical properties; Organic chemistry; Photostructural changes; Physics; Physics and Astronomy; Processes; Raman spectra; Spectrum analysis; Surfaces and Interfaces; Thin Films; X ray analysis
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-019-3194-4

The paper reports the photo-induced effects on the optical and structural properties of ternary Ge 30 Se 70− x Bi x ( x  = 5, 10) thin films illuminated with 532 nm green laser light. The material exhibits photo-bleaching nature when exposed to laser light for a prolonged time. The amorphous nature sustains after laser irradiation as detected by X-ray diffraction. The chemical composition of the deposited thin film was examined by energy dispersive X-ray analysis. Field emission scanning electron microscopy investigation showed that the surface morphology was influenced by the laser irradiation. The transmission spectra were collected from UV–Vis-NIR spectroscopy which shows the films exhibit indirect allowed transition. The other optical parameters were calculated from the transmission spectra. The linear optical properties were influenced by the laser-induced phenomena. The photobleaching is explained on the basis of homopolar bond breaking and formation of heteropolar bonds with photon energy. The Raman spectra provided the evidence of photo structural changes in the films.