Study of Absorption Spectra for GeSnSe Glasses

Abstract

The Ge1‐xSnxSe2.5 system is prepared by melting the proper ratio of high purity elements in evacuated quartz ampoules followed by quenching in ice‐water mixture. The glassy state can be formed when 0 ≦ x ≦ 0.4, while increasing Sn content to x = 0.6 a partially crystalline ingot is formed. Ge1‐xSnxSe2.5 thin films (0 ≦ × ≦ 0.6) are deposited by the thermal evaporation technique in the thickness range 80 to 400 nm. The optical absorbance spectra of thin films are studied as a function of composition and film thickness. The optical band gap is determined and found to be due to indirect transitions and to be a function of film thickness. Increasing tin content leads to a decrease of the optical band gap. The influence of composition on the Urbach tail width is reported and the implications are discussed.

Effect of Sn addition on the optical gap and far-infrared reflectivity spectra of amorphous Sb–Se films

“…Both the parameters along with the average coordination number (Z) and R-value [5] for different compositions are summarized in [3]. Similar effect in the optical gap has also been observed with the Sn substitution for Ge in amorphous Ge-Se system [10]. The inset of Fig.…”

On the study of the optical constants for different compositions of Sn x (GeSe)100−x thin films in terms of the electronic polarizability, electronegativity and bulk modulus

“…The variation of Ge-Se structure with increasing Ge content affected the physical properties such as the glass-forming regions, glass transition temperature, photoluminescence, IR, Raman spectra and the optical properties [10][11][12]. The addition of a third element such as tin into Ge-Se system will enlarge their glass-forming area and improve their physical properties [13][14][15]. Moreover, Ge-Se-Sn chalcogenide glasses have gained more attention due to their applications in various solid-state devices such as memory, switching, space-charge-limited current, photovoltaic devices, infrared filters, xerographic machines and X-ray imaging [16][17][18][19][20].…”

Effect of annealing temperature on the structural and optical properties of Ge15Se75Zn10 thin films

“…The results revealed that the refractive index and oscillator strength increase with Sn fraction while the optical band gap energy (E G ) decreases. Ali et al [35] investigated the absorption spectra of Ge 1-x Sn x Se 2.5 thin film (0 ≤ x ≤ 0.6) glasses. It has been reported that the glassy state can be formed when 0 ≤ x ≤ 0.4 and the glass matrix partially crystallized at x = 0.6.…”