Ellipsometric and Spectrometric Studies of (Ga0.2In0.8)2Se3 Thin Film

Abstract

Thermal evaporation technique is used to deposite (Ga0,2In0,8)2Se3 thin films. The refractive index and extinction coefficient dispersions are obtained from the spectral ellipsometry measurements. The dispersion of the refractive index is described in the framework of the Wemple–Di Domenico model. The optical transmission spectra of a (Ga0,2In0,8)2Se3 thin film are studied in the temperature range 77–300 K. The temperature behavior of the Urbach absorption edge, as well as the temperature dependences of the energy pseudogap and Urbach energy, are investigated. The influence of different types of disordering on the optical absorption edge of a (Ga0,2In0,8)2Se3 thin film is discussed. Optical parameters of a (Ga0,2In0,8)2Se3 thin film and a single crystal are compared.

Materials for Optical Sensors of X-ray Irradiation Based on (GaxIn1 – x)2Se3 Films

“…where 𝐸 U (𝑇 ) is the Urbach energy, 𝛼 0 and 𝐸 0 are the coordinates of the convergence point of the Urbach bundle, ℎ𝜈 and 𝑇 are the photon energy and temperature, respectively. It should be noted that, similarly to (Ga 𝑥 In 1−𝑥 ) 2 Se 3 crystals, the optical absorption edge in (Ga 𝑥 In 1−𝑥 ) 2 Se 3 films is also described by the Urbach relation [31][32][33]. It is worth to mention that the temperature variation of the Urbach absorption edge in the thin films under study sim-ilarly to that of the single crystals is explained by the electron-phonon interaction (EPI).…”

“…In recent years, the studies of the preparation of (Ga 𝑥 In 1−𝑥 ) 2 Se 3 mixed crystals in the form of films were performed for their effective practical application [11][12][13]. In Refs.…”

“…In Refs. [11][12][13], the refractive index and extinction coefficient dispersions were measured by spectral ellipsometry, as well as the temperature behavior of the Urbach absorption edge and the temperature dependences of the optical parameters were studied. Investigations of the influence of the different types of irradiation (in particular, X-ray irradiation) on physical parameters of thin films were determined by their application to the development of large-area, flexible, and light-weight radiation detectors [14].…”

Optical Parameters of As-Deposited and Annealed (Ga0.3In0.7)2Se3 Thin Films

“…In recent years, the studies for preparing of (Ga 𝑥 In 1−𝑥 ) 2 Se 3 solid solutions in the form of thin films were performed for their effective practical application [10]. In Ref.…”

“…In Ref. [10], the refractive index and extinction coefficient dispersions were measured by spectral ellipsometry, and the temperature behavior of the Urbach absorption edge and the temperature dependences of the optical parameters were stud- ied. The influence of X-ray irradiation on such optical parameters of (Ga 𝑥 In 1−𝑥 ) 2 Se 3 films as the energy pseudogap, Urbach energy, and refractive index have been investigated in [11,12].…”