Photo and thermally induced properties change in Bi/Ag/Se trilayer thin film

ABSTRACT

In this article, we have demonstrated the optical and structural properties change in Bi/Ag/Se trilayer thin films by the influence of thermal and photon energy. The trilayer films prepared by thermal evaporation technique were annealed and laser irradiated at room temperature. The X-ray diffraction study revealed the Ag₂Se phase formation and the surface morphology change is being studied by Field emission scanning electron microscopy. The optical properties of the studied films were characterized by using FTIR spectrophotometer in the wavelength range 400–1200 nm. The reduction of optical band gap by both thermal and laser irradiation is being discussed on the basis of chemical disorderness, defect states and density of localized states in the mobility gap. The Raman shift due to annealing and irradiation supports the changes in the film. The large change in optical band gap in thermal annealing is useful for memory device and waveguide fabrication.

KEYWORDS:

• Trilayer thin films
• optical properties
• band gap
• annealing
• laser irradiation

Acknowledgements

The authors thank DST, Govt. of India for the financial support (No. DST-INSPIRE Faculty/IFA-PH-11), Department of Physics, Indian Institute of Science (IISc.) for optical study, NISER, Bhubaneswar for the FESEM study.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Department of Science and Technology, Ministry of Science and Technology: [Grant Number DST-INSPIRE/IFA-PH-11].