Nanocrystalline embedded In2Se3 amorphous thin film investigation and optical enhancement characterization for photo-sensing application

AbstractIn this investigation, highly adherent and unique advantageous properties of In2Se3 films were prepared for different studies and applications using a thermal evaporation technique under a high vacuum on different substrates (including glass, quartz, and a p-Si single crystal). X-ray diffraction results show that the prepared In2Se3 powder has a polycrystalline nature with α-phase. The average size of the crystallite, microstrain, and dislocation density was measured and found to be 273.6 nm, 4.9 × 10–3, and 1.34 × 10–5 nm−2, respectively. Due to the long-range array, the deposited In2Se3 films have an amorphous nature. SEM images of the film surface were measured to examine the RMS roughness features and grain-boundary effect. Spectrophotometer measurements of transmittance and reflectance were used to estimate the optical constants of In2Se3 films. The relationship between absorption coefficient and photon energy was tested, and the results revealed that the optical transition is directly allowed with an energy gap of 2.25 eV. The dispersion and oscillator energies were measured using the single oscillator model employing a relation of Wemple–DiDomenico and found to be 3.8 and 1.7 eV. The characteristics of the In2Se3-based junction showed promising candidates for photosensor applications under illumination. Graphical abstract