Preparation and investigation of structure, optical, nonlinear optical and thermoelectric properties of Bi ₂ Se ₃ thin film

Abstract

Bi 2 Se 3 thin film were prepared using vacuum thermal evaporation technique. the structure and surface topography for this sample were investigated using both of Diffraction Electron Microscope photos (DEM) and Transmission Electron Microscope (TEM). Bi 2 Se 3 thin film had a direct energy gap which was determined by using measured optical parameters such as optical transmittance (T) and optical reflectance (R). The values for both of the oscillating energy ( E o ) ,dispersion energy (E d ) and ratio of the free carrier concentration on the effective mass (N/m*) were determined optically using the calculated values of refractive index (n). The dielectrical parameters such as dielectric loss (ε \ ) and dielectric tangent loss dielectric loss (ε \\ ) were calculated. The density of states (DOS) for both of valence band (N v ) and conduction band (N c ) and also position of Fermi level were determined. The nonlinear optical results such as third-order nonlinear optical susceptibility (χ (3) ), nonlinear refractive index (n 2 ) and nonlinear absorption coefficient (β c ) were determined. The influence of temperature on IV results were studied, finally the dependence of all of Dispersion factor (D), parallel inductance (L p ) and Seebeck coefficient (S) values on temperature for this film were studied. Keywords:-Bi 2 Se 3 thin film, Optical properties, dielectrical results, nonlinear optical properties, IV characterization and thermoelectric results.

Enhanced Photoresponse and Surface Wettability of Bi2Se3 Film with Annealing at Different Temperatures for Optoelectronic Applications

“…The capacitance and electrical resistivity of the Bi 2 Se 3 films were strongly affected by annealing. The increase in electron mobility with temperature increased the IV characteristics . The prime novelty of this work is to analyze the impact of the annealing process on the Bi 2 Se 3 thin films.…”