Aging process of photosensitive chalcogenide films deposited by electron beam deposition
Aging process of photosensitive chalcogenide films deposited by electron beam deposition
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DOI：
10.1016/j.jallcom.2011.04.054
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发表时间：
2011-07-07
影响因子：
6.2
通讯作者：
Nazabal, V.
中科院分区：
文献类型：
--
作者：
Charpentier, F.;Dussauze, M.;Nazabal, V.
硫族化物薄膜因其用作窄带通滤波器、全向反射器包层、全光信号处理装置或光化学传感器等光学元件而引起广泛关注。使用相应的块状玻璃作为靶材，通过电子束沉积 (EBD) 沉积 Ge15Sb20S65 和 As30Se50Te20 硫族化物非晶薄膜。通过远红外和拉曼光谱研究了体膜和薄膜的结构。这项研究通过将硫族化物薄膜在大气条件下暴露在自然光下六个月的时间，研究了硫族化物薄膜的普通老化行为。人们发现这两种薄膜都具有光敏性，这通过它们的光学带隙根据化学成分向更短或更长的波长移动而表明。人们发现老化也会引起形态变化，最明显的是三氧化二砷微晶可能在 As30Se50Te20 薄膜表面生长。我们从光氧化和光水解现象的角度讨论了这种效应，发现对于 Ge25Sb10S65 薄膜来说，其程度相对有限。后者薄膜对表面晶体生长的较大稳定性与锗与锗-硫氧化物四面体排列中的扩散氧原子结合的能力有关。 (C) 2011 Elsevier B.V. 保留所有权利。
Chalcogenide films attract broad interest due to their use as optical components like narrow band-pass filters, omnidirectional reflectors cladding, all-optical signal processing devices or optochemical sensors. Ge15Sb20S65 and As30Se50Te20 chalcogenide amorphous films were deposited by electron beam deposition (EBD) using their corresponding bulk glasses as targets. The structure of both bulk and thin film has been studied by far-IR and Raman spectroscopy. This study investigated an ordinary aging behavior of the chalcogenide films by exposing them to natural light under atmospheric conditions for a period of six months. Both films were found to be photosensitive as manifested by the shift of their optical band-gap to shorter or longer wavelength depending on chemical composition. Aging was found to induce also morphological changes, most notably the likely growth of arsenic trioxide microcrystals on the surface of As30Se50Te20 films. Such effects were discussed in terms of photo-oxidation and photo-hydrolysis phenomena, the extent of which was found to be relatively limited for Ge25Sb10S65 films. The larger stability of the latter films against crystal growth at the surface was associated with the ability of germanium to bond to diffusing oxygen atoms in germanium-oxysulfide tetrahedral arrangements. (C) 2011 Elsevier B.V. All rights reserved.