Determination of Kinetic Parameters of Bi2Se3 Thin Films by Computation

Abstract

Bi2Se3 thin films are prepared by thermal evaporation method onto well-cleaned glass substrates. From the XRD analysis, the film is found to be amorphous in nature. Thermal analysis of Bi2Se3 sample scraped off from the glass substrate is performed using the technique differential scanning calorimetry (DSC) at different heating rates. Kissinger method is used to analysis these constant heating rate spectra and the activation energy 'Ea′ corresponding to the phase transformation is calculated through the examination of the DSC peak temperature shift induced by variation of the heating rate. An analytical equation with three kinetic parameters (activation energy (Ea), transformation order (n) and the frequency factor (v)) is derived from the Johnson-Mehl-Avrami (JMA) theory to describe the constant heating rate DSC spectra. Using the activation energy from Kissinger plot, theoretical constant heating rate DSC traces are generated for arbitrary values of 'v' and 'n' using the analytical equation. Finally, theoretically generated DSC spectra is compared with that of the experimental one and the unknown values 'v' and 'n' are determined.