Surface topography and optical properties of Ge-Sb(As)-S-Te thin films by atomic-force microscopy and variable angle spectroscopic ellipsometry

Dulgheru, Nicoleta; Anastasescu, Mihai; Nicolescu, M.; Stoica, M.; Gärtner, M.; Pamukchieva, V.; Szekeres, A.; Todorova, K.

doi:10.1088/1742-6596/356/1/012019

Cited by 3 publications

(1 citation statement)

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“…Figure 3 indicates the value of the absorption coefficient, the increase/decrease of the Ge/Sb content upon photon energy incident for all the samples of Refractive index can be obtained using the normal incidence reflectance according to Fresnel's equations [12,13] computed by relation (4): Figure 5 shows the results obtained by the refractive index according to (4). The value of the refractive index and extinction coefficient decrease/ increase with Ge / Sb content [14][15][16][17]. The optical band gap E g was derived assuming indirect transitions between the edge of the valence and conduction band.…”

Section: Experimental Details and Resultsmentioning

confidence: 99%

On the optical nonlinearity in the GeSbSe chalcogenide glasses

Dulgheru

Chiroiu

Munteanu

et al. 2020

Mater. Res. Express

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Chalcogenide glasses Ge x Sb 40−x Se 60 with composition 12, 25 and 30 at.%, synthesized from elements with 5N purity (Ge, Sb, Se) by the conventional melt-quenching method were studied. The spectrophotometer's measurements were recorded to determine the optical properties. Models based on the absorbance and absorption coefficient are used to determine the optical band-gap energy. The Urbach energy is deduced in the -Ge Sb Se x x 40 60 thin film alloys with composition x=12, 25 and 30 at.%. The electronic and structural properties are studied, and the influence of the Urbach energy in estimating of the nonlinearity in the optical properties of these glasses is discussed. The analysis is performed with respect to the Urbach parameter that quantifies the degree of crystallinity of the structure which can be used to understand the behavior of different diffractive, wave-transmission and fiber structures.

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