若干硫系（卤）玻璃的光诱导效应和离子导电性能研究

【作者】 严祁祺；

【导师】 陈国荣；

【作者基本信息】 华东理工大学 ， 材料科学与工程， 2013， 博士

【摘要】 本文主要研究了若干硫系(卤)玻璃的光诱导效应和离子电导率方面的性能。首先系统研究了不同稀土和过渡金属离子掺杂Ge-Ga-S-CsCl系统硫卤玻璃的光致发光性能,其次探讨了以Ge-Se硫系薄膜为主的光致漂白和光致暗化效应,最后对新系统硫卤玻璃Ge-Ga-S-AgI-Ag的物理化学性能以及离子电导率进行了讨论。主要研究成果如下：在Ge-Ga-S-CsCl硫卤玻璃基质中,Eu2+离子掺杂只有当CsCl含量达到40mo1.%时才能在395nm激发下获得中心位于433nm的宽峰发射,而Mn2+离子掺杂在447nm激发下,随着Mn2+离子含量的增加,发生由绿光发射向红光发射的转移。Eu2+离子和Mn2+离子共掺则在395nm的激发下发射出很强的属于Mn2+离子的黄光,通过计算测得的Eu2+离子单掺的发光寿命和Eu2+-Mn2+离子共掺的发光寿命,得到Eu2+向Mn2+能量传递的最大效率达到91%,同时讨论了可能的能量传递过程。Eu2+-Mn2+离子共掺之后吸收截面积的显著增大也是Mn2+离子黄光发射得到增强的原因。由激发和发射光谱及荧光寿命测试结果证实,Ce3+-Yb3+离子共掺在450nm激发下实现了量子剪裁效应,即吸收一个可见光子发射出两个近红外光子。Ce3+向yb3+能量传递的最大效率可以达到82%,Yb3+离子发光的量子效率达到119%。讨论了可能的能量传递过程机理。同样,由激发和发射光谱及荧光寿命测试结果证实,Eu2+-Yb3+离子共掺在395nm激发下实现了量子剪裁效应。Eu2+向yb3+能量传递的最大效率可以达到85%,能量传递是按照偶极-偶极相互作用实现的,也讨论了可能存在的能量传递过程机理。通过吸收和光致发光光谱研究了Bix/Tm3+单掺和共掺的70GeS2-10Ga2S3-20KBr硫系玻璃的光学性能。结果显示在808nm的激发下,Bix/Tm3+共掺样品在1230nm和1470nm处的发射都得到了增强。提出了可能存在的Bix到Tm3+离子的能量传递过程。通过实时透射光谱的测试研究了GeSe2阳Ge2Se3薄膜分别在空气和真空中的光致能带变化现象。用与能带能量相当的激光在空气中辐照足够长的时间,两种薄膜都呈现出光致漂白的效应。通过对比空气中和真空中的光致能带变化,发现Ge2Se3薄膜的光致漂白是由于表面的光致氧化造成的,而GeSe2薄膜光致漂白则由内部结构变化占主导地位。探索了非晶硫系薄膜xGe45Se55-(1-x)As45Se55(x=0,0.25,0.5,0.75,1)在660nm激光辐照下的光敏感性。随着Ge45Se55含量从0增大到1,光致能带变化效应从光致暗化向光致漂白转变。光致漂白的程度和薄膜组成中Ge-Ge键浓度相关。光致漂白和光致暗化的动力学可以用伸缩指数幂方程来描述。光致漂白的动力学反应比光致暗化薄膜要快很多。通过密度、X射线衍射、拉曼光谱、化学稳定性、可见-近红外-红外透过光谱、以及离子电导率等性能测试,研究了新系统GeS2-Ga2S3-AgI-Ag硫卤玻璃。该系统有较大的玻璃形成区,Ag单质的引入量最高达20mol.%,离子电导率最高达～10-5S/cm。在结构分析基础上,讨论了AgI的引入对玻璃离子电导率的贡献。此外,该系统玻璃在空气中的化学稳定性相比同组成的GeS2-Ga2S3-LiI和GeS2-Ga2S3-CsI系统硫卤玻璃有显著提高。更多还原

【Abstract】 The thesis emphasizes on photoinduced optical properties and ionic conductivity property of chalcohalide and/or chalcogenide glasses. First, the photoluminescence properties of different rare-earth and transition metal ions doped Ge-Ga-S-CsCl chalcohalide glasses are investigated. Second, photoinduced darkening and bleaching of Ge-Se chalcogenide films are studied. At last, the physical and chemical properties as well as ionic conductivity of new chalcohalide glass system Ge-Ga-S-Agl-Ag are researched. Main achieved results are listed as follow:Eu2+single doped chalcohalide glass can emit a broad peak centered at433nm under the excitation of395nm only when the CsCl content of glass is up to40mol.%, while the emission of Mn2+single doped chalcohalide glass transits from green to red as the concentration of Mn2+increases upon447nm excitation. Notably enhanced Mn2+yellow emission is observed in CsCl modified and Eu2+/Mn2+codoped Ge-Ga-S glasses under395nm excitation. The plausible efficiency of energy transfer (ET) from Eu2+to Mn2+is as high as91%, which is obtained by measurement of luminescence decay of Eu2+in samples doped with and without Mn2+. The Eu2+/Mn2+codoping significantly increases the excitation cross-section at the NUV region, which is at heart of the enhanced Mn2+yellow emission. The ET processes responsible for the enhanced luminescence are discussed.Excitation, emission and decay spectra are measured to prove the occurrence of near-infrared (NIR) quantum cutting involving the emission of two NIR photons for each visible photon absorbed from Ce3+/Yb3+codoped chalcohalide glasses. The maximum ET efficiency from Ce3+to Yb3+obtained is as high as82%. The directly measured and calculated quantum yield (QY) of Yb3+emission is up to119%. The possible mechanism of ET is discussed. Besides, Excitation, emission and decay spectra are measured to prove the occurrence of near-infrared (NIR) quantum cutting of Eu2+/Yb3+codoped chalcohalide glasses.The maximum ET efficiency obtained is as high as85%. The ET from Eu2+to Yb3+is followed by dipole-dipole interaction. The possible mechanism of ET is also discussed.Near infrared luminescence properties of Bix Tm3+-doped and Bix/Tm3+co-doped70GeS2-10Ga2S3-20KBr chalcohalide glass samples are investigated by the absorption and photoluminescence spectra. The enhanced emissions at1230and1470nm have been observed from Bix Tm3+co-doped samples when pumped by an808laser diode. The possible energy transfer mechanisms from Bix to Tm3+ions are proposed.Photo-induced effects of GeSe2and Ge2Se3films illuminated in air and in vacuum are investigated by in-situ transmission spectra measurements. Both compositions exhibit photobleaching (PB) when exposed to bandgap laser for a prolonged time in air. By comparing with the photoinduced effects in vacuum, PB in Ge2Se3film results from surface photo-oxidation, whereas intrinsic structural changes dominate the PB in GeSe2film.Photosensitivity of thermally evaporated chalcogenide amorphous films of xGe45Se55-(1-x)As45Se55(x=0,0.25,0.5,0.75,1) composition is investigated when exposed to the laser light of660nm wavelength. The photo-induced effects transition from photodarkening (PD) to photobleaching (PB) as Ge4sSe55x increases from0to1. The degree of PB correlates with the concentration of Ge-Ge homopolar bonds. The kinetics of PD and PB can be well described by a stretched exponential function. The dynamic response of PB is much faster than that of PD films in the present glass system.The new chalcohalide glass system Ge-Ga-S-AgI-Ag is investigated by the measurement of density, X-ray diffraction, raman spectra, chemical stability, visible-near infrared-infrared transmission spectra as well as ionic conductivity. The doped Ag metal content in the system is up to20mol.%. The chemical stability of the glass system in air is much better than the same composition of Ge-Ga-S-CsI and Ge-Ga-S-Lil. The contribution of AgI to ionic conductivity is also discussed based on the structure analysis.更多还原