A study of optical absorption and photoinduced effects in Ge–Se–Te amorphous system

Abstract

Optical studies have been performed on amorphous films of the system Ge10Se90-xTex where (x = 20, 30, 40). The study revealed that as the Te content is increased, the optical band gap (Eg) was found to decrease. Photoinduced effects were studied on thin films samples irradiated with either white light or uv light. The shift in Eg due to photoirradiation disappears upon annealing the films at a temperature below the glass transition temperature. The effect of γ-radiation up to 8 kGy on the optical band gap was also investigated, and no detectable shift of the optical band gap was observed. The relationship between the optical band gap and both the average heat of atomization and the average coordination number of the compositions under investigation was studied.

Optical properties of GexSb20−xTe80 thin films and their changes by light illumination

“…The E gi values are below 1 eV. It has been observed for Ge 10 Se 90Àx Te x systems that increasing the Te content up to 40 at.% results in narrowing the optical bandgap energy down to 1.2 eV [7]. Our films contain twice-higher amount of Te, and therefore, E gi values less than 1 eV are reasonable.…”

Effect of the Germanium on the Crystallization Kinetics of Se-Te Glassy Alloy

“…SHIMADZU DTG-60, simultaneous TG/DTA module is used to measure the caloric manifestation of the phase transformation and to study the crystallization kinetics under non-isothermal conditions. The TG/DTA scans are taken at four heating rate (10,15,20,25 • Cmin −1 ) for the four different composition in the micro alumina pans under dry nitrogen gas. The masses of the samples varied between10 and 30 mg.…”

“…The addition of a third element Ge expands the glass forming area and also creates compositional and configurational disorder in the system. Ge-doped chalcogenide glasses become attractive materials for fundamental research of their structure, properties and preparation [10][11][12][13]. Germanium chalcogenide glassy alloys belong to an interesting and unique class of amorphous materials and have wide technical applications in electronic and optoelectronic devices.…”

Novel Binary Calcia–Alumina Systems for Device Applications

“…where the parameter ETauc represents the Tauc's energy gap and B is a constant depending on the minimum metallic conductivity σo, refractive index μ, the width of band edges ΔE and the nature of electronic transition [109][110][111].…”

“…where N(E) is DOS (that is the number of available states for occupation at each energy level), mr is the reduced effective mass (related to the electrons and holes effective mass) [109][110][111]. …”