Urbach rule in photoelectron emission from surface states of low-sized silica
Urbach rule in photoelectron emission from surface states of low-sized silica
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低尺寸二氧化硅表面态光电子发射的 Urbach 规则
DOI：
10.1016/j.jnoncrysol.2008.11.041
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发表时间：
2009
影响因子：
3.5
通讯作者：
E. Buntov
中科院分区：
文献类型：
--
作者：
A. Zatsepin;E. Buntov
研究了近紫外区二氧化硅薄膜和纳米压坯表面(界面态)光电子发射的光谱特性和温度特性。用冻结声子概念和修正的三级电子发射模型对它们进行了解释。提出了小颗粒二氧化硅的光学Urbach规则的电子发射模拟。光学吸收阶段被认为是电子发射过程的主导阶段。得到了所研究样品的结构和能量参数。结果表明，由于电子输运条件的不同，薄的和厚的二氧化硅薄膜具有相似的结构参数，但它们的有效势垒不同。致密的二氧化硅纳米粉末具有很高的静态结构无序值，这是由于其超分散结构的特殊性。
Spectral and temperature dependences of photoelectron emission from surface (interface) states of SiO2films and nanocompacts in the near UV region were studied. They were interpreted in terms of ‘frozen phonons’ conception and modified three-stage electron emission model. The electron emission analog of optical Urbach rule for low-sized silica was proposed. Optical absorption stage was recognized as the dominant phase of electron emission process. The structure and energy parameters of studied samples were obtained. It was revealed that thin and thick SiO2films have similar structure parameters while their effective potential barriers differ because of different electron transport conditions. High value of static structural disorder in compacted SiO2nanopowders is attributed to peculiarities of their ultradispersed structure.