Composition dependent structural phase transition and optical band gap tuning in InSe thin films
Harpreet Singh,
Palwinder Singh,
Randhir Singh,
Jeewan Sharma,
A.P. Singh,
Akshay Kumar,
Anup Thakur
Affiliations
Harpreet Singh
Department of Physics, Punjabi University, Patiala, 147 002, Punjab, India; Advanced Materials Research Lab, Department of Basic and Applied Sciences, Punjabi University, Patiala, 147 002, Punjab, India
Palwinder Singh
Department of Physics, Punjabi University, Patiala, 147 002, Punjab, India; Advanced Materials Research Lab, Department of Basic and Applied Sciences, Punjabi University, Patiala, 147 002, Punjab, India
Randhir Singh
Department of Nanotechnology, Sri Guru Granth Sahib World University, Fatehgarh Sahib, Punjab, 140 407, India
Jeewan Sharma
Department of Nanotechnology, Sri Guru Granth Sahib World University, Fatehgarh Sahib, Punjab, 140 407, India
A.P. Singh
Department of Physics, Dr. B. R. Ambedkar National Institute of Technology, Jalandhar, Punjab, 144 011, India
Akshay Kumar
Department of Nanotechnology, Sri Guru Granth Sahib World University, Fatehgarh Sahib, Punjab, 140 407, India
Anup Thakur
Advanced Materials Research Lab, Department of Basic and Applied Sciences, Punjabi University, Patiala, 147 002, Punjab, India; Corresponding author.
Bulk alloys of InxSe100-x (x = 5, 10, 20, 30, 40 and 50) are prepared using melt quenching technique. Thin films having thickness ~750 nm of these prepared bulk alloys are fabricated using thermal evaporation technique on glass substrate. The as-deposited InxSe100-x thin films with x ≤ 40 are amorphous and In50Se50 thin film is crystalline in nature verified from X-ray diffraction (XRD). The change in morphology of deposited thin films with indium content also verifies structural phase transition and found that the phase transition started with x = 40 which is not detected in XRD pattern. The drastic change in transmission is found with 50% indium content. In50Se50 thin film has less than 30% transmission whereas other films are highly transparent. Optical band gap is calculated using Tauc's plot and decrease in optical band gap is observed with indium content. The variation of optical band gap from 1.88 eV to 1.12 eV is achieved with indium content of 5%–50%. The structural transition and change in optical band gap depict that InSe thin films are potential candidates in various technological applications.
