Photochemical process of divalent germanium responsible for photorefractive index change in GeO2-SiO2 glasses.
Photochemical process of divalent germanium responsible for photorefractive index change in GeO2-SiO2 glasses.
复制标题
DOI：
10.1016/j.jnoncrysol.2004.08.037
复制
发表时间：
2003-10
期刊：
影响因子：
3.8
通讯作者：
Akifumi Sakoh;Masahide Takahashi;T. Yoko;J. Nishii;Hiroaki Nishiyama;I. Miyamoto
中科院分区：
文献类型：
--
作者：
Akifumi Sakoh;Masahide Takahashi;T. Yoko;J. Nishii;Hiroaki Nishiyama;I. Miyamoto
利用激发-发射能量图研究了不同光敏性的GeO 2-SiO2玻璃中二价Ge（Ge ~（2+））中心的光致发光谱，并将紫外光诱导的光致发光活性与Ge ~（2+）中心周围的局域结构联系起来。具有较大的光致发光活性的玻璃倾向于表现出更大的单重态-单重态跃迁的带展宽，伴随着斯托克斯位移的增加，以更高的激发能量。这强烈表明存在具有较高激发能的高光敏Ge 2+中心。还发现，羟基或硼物种的引入改变了Ge 2+的局部环境，导致增强的光致发光活性。
The photoluminescence spectra of the divalent Ge (Ge2+) center in GeO2–SiO2glasses with different photosensitivities were investigated by means of excitation-emission energy mapping to correlate the ultraviolet light induced photorefractivity with the local structure around the Ge2+centers. The glasses with a larger photorefractivity tended to exhibit a greater band broadening of the singlet–singlet transition to higher excitation energies accompanied by an increase in the Stokes shifts. This strongly suggests the existence of a highly photosensitive Ge2+centers with higher excitation energies. It was also found that the introduction of a hydroxyl group or boron species modifies the local environment of Ge2+leading to an enhanced photorefractivity.