Structure and optical properties of amorphous GeSx films prepared by PLD

Pan, Ruikun; Tao, Haizheng; Zang, H.C.; Lin, Changgui; Zhang, T.J.; Zhao, Xiujian

doi:10.1016/j.jnoncrysol.2010.11.055

Cited by 21 publications

(12 citation statements)

References 25 publications

(44 reference statements)

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“…In the present experiment, a white light of xenon lamp was used. In the figure, the transmission of the light with the wavelength of 397 nm, which has greater energy (3.12 eV) than the optical gap, 2.59 eV, 25 is shown. Supposing that the light is used to excite lone-pair electrons to anti-bonding states on chalcogen (S) atoms, the efficiency of the photo-excitation should be proportional to the transmission of light whose energy has greater than the optical gap, and "chalcogen atoms" should be exposed to the light.…”

Section: Kinetics Of Silver Photo-diffusionmentioning

confidence: 99%

Silver photo-diffusion and photo-induced macroscopic surface deformation of Ge33S67/Ag/Si substrate

Sakaguchi

Asaoka

Uozumi

et al. 2016

Journal of Applied Physics

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Ge-chalcogenide films show various photo-induced changes, and silver photo-diffusion is one of them which attracts lots of interest. In this paper, we report how silver and Ge-chalcogenide layers in Ge 33 S 67 /Ag/Si substrate stacks change under light exposure in the depth by measuring timeresolved neutron reflectivity. It was found from the measurement that Ag ions diffuse all over the matrix Ge 33 S 67 layer once Ag dissolves into the layer. We also found that the surface was macroscopically deformed by the extended light exposure. Its structural origin was investigated by a scanning electron microscopy. Published by AIP Publishing. [http://dx

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Section: Kinetics Of Silver Photo-diffusionmentioning

confidence: 99%

Silver photo-diffusion and photo-induced macroscopic surface deformation of Ge33S67/Ag/Si substrate

Sakaguchi

Asaoka

Uozumi

et al. 2016

Journal of Applied Physics

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“…In some cases, these structures largely differ (in terms of quantity of defects) from those obtained by the common melt-quenching (MQ) technique used for the preparation of bulk glasses. It appears that g-GeS x (with x = 2, 4, 6) films, obtained by pulsed laser deposition from the pristine bulk glasses (obtained by MQ), show a significant content of defects and "wrong bonds" [7][8][9]. In this case, the departure from perfect chemical order is due to the fact that as-deposited g-GeS x films are far away from the equilibrium state [7].…”

Section: Introductionmentioning

confidence: 99%

“…As a subclass of these materials, chalcogenide glassy films are useful for many applications such as optoelectronic and nonvolatile memory devices [4,5]. For example, amorphous Ge 2 Sb 2 Te 5 and GeS x films prepared by deposition techniques can be used as phasechange and optical materials, respectively [6,7]. The structure and chemical order of these films are found to be strongly dependent on the chalcogenide composition and conditions used for the deposition.…”

Section: Introductionmentioning

confidence: 99%

“…It appears that g-GeS x (with x = 2, 4, 6) films, obtained by pulsed laser deposition from the pristine bulk glasses (obtained by MQ), show a significant content of defects and "wrong bonds" [7][8][9]. In this case, the departure from perfect chemical order is due to the fact that as-deposited g-GeS x films are far away from the equilibrium state [7]. For the case of glassy GeS 2 (g-GeS 2 , g standing hereafter for glass), we recall that perfect chemical order corresponds to the absence of any undercoordinated or overcoordinated Ge atoms or S atoms ( =4 and =2 for Ge and S, respectively).…”

Section: Introductionmentioning

confidence: 99%

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Surface of glassyGeS2: A model based on a first-principles approach

et al. 2014

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First-principles calculations within the framework of the density functional theory are used to construct realistic models for the surface of glassy GeS 2 (g-GeS 2 ). Both calculations at T = 0 K and at finite temperature (T = 300 K) are considered. This allows for a comparison between the structural and electronic properties of surface and bulk g-GeS 2 . Although the g-GeS 2 surface recovers the main tetrahedral structural motif of bulk g-GeS 2 , the number of fourfold coordinated Ge atoms and twofold coordinated S atoms is smaller than in the bulk. On the contrary, the surface system features a larger content of overcoordinated S atoms and threefold coordinated Ge atoms. This effect is more important for the g-GeS 2 surface relaxed at 0 K. Maximally localized Wannier functions (WF) are used to inspect the nature of the chemical bonds of the structural units present at the g-GeS 2 surface. We compare the ability of several charge derivation methods to capture the atomic charge variations induced by a coordination change. Our estimate for the charges allows exploiting the first-principles results as a data base to construct a reliable interatomic force field.

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“…In some cases, these structures largely differ (in terms of quantity of defects) from those obtained by common melt-quenching methods used for the preparation of bulk glasses. It appears that glassy GeS x (with x = 2, 4, 6) films, obtained by pulsed laser deposition from the pristine bulk glasses, show a significant content of defects and "wrong bonds" (such as homopolar bonds) [42][43][44]. In this case, the departure from perfect chemical order is due to the fact that as-deposited g-GeS x films are far away from the equilibrium state [42][43][44].…”

Section: Chalcogenide Surfacesmentioning

confidence: 99%

Molecular Modeling of Glassy Surfaces

Ori

Massobrio

Bouzid

et al. 2015

Springer Series in Materials Science

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Progress in computational materials science has allowed the development of realistic models for a wide range of materials including both crystalline and glassy solids. In recent years, with the growing interest in nanoparticles and porous materials, more attention has been devoted to the design of realistic models of glassy surfaces and finely divided materials. The structural disorder in glassy surfaces, however, poses a major challenge which consists of describing such surfaces using computer simulations. In this paper, we show how atomic-scale simulations can be used to develop and investigate the properties of glassy surfaces. We illustrate how both first principles calculations and classical molecular mechanics can be used to follow the trajectory at finite temperature of these systems, and obtain statistical thermodynamic averages to compare against available experiments. Both glassy oxide (silica) and non-oxide (chalcogenide) surfaces are considered.

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Structure and optical properties of amorphous GeSx films prepared by PLD

Cited by 21 publications

References 25 publications

Silver photo-diffusion and photo-induced macroscopic surface deformation of Ge33S67/Ag/Si substrate

Silver photo-diffusion and photo-induced macroscopic surface deformation of Ge33S67/Ag/Si substrate

Surface of glassyGeS2: A model based on a first-principles approach

Molecular Modeling of Glassy Surfaces

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