Surface versus bulk electronic/defect structures of transparent conducting oxides: I. Indium oxide and ITO
Surface versus bulk electronic/defect structures of transparent conducting oxides: I. Indium oxide and ITO
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DOI：
10.1088/0022-3727/39/18/006
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发表时间：
2006-09-21
影响因子：
3.4
通讯作者：
Klein, A.
中科院分区：
文献类型：
--
作者：
Harvey, S. P.;Mason, T. O.;Klein, A.
用X射线光电子能谱和紫外光电子能谱对制备的In_2O_3和掺锡In_2O_3(ITO)块体陶瓷样品在真空和氧气气氛中热处理前后的样品进行了分析。在非原位制备的陶瓷样品上的结果表明，在芯能级、费米能级和电离势方面与原位沉积测量的薄膜的结果是相似的。这为快速合成和筛选其他透明导电氧化物(TCO)材料的表面电子缺陷性质提供了一条可行的途径。由于方铅矿结构独特的晶体缺陷性质，In_2O_3基TCO的表面电子缺陷结构与其潜在的电子缺陷结构之间存在着很强的相关性。这会导致在表面形成化学耗尽，并在较高的制备温度下形成过氧化氢表面物种。讨论了ITO作为空穴注入电极在有机电致发光器件中的应用。
Carefully prepared bulk ceramic specimens of In2O3 and Sn-doped In2O3 (ITO) were analysed with x-ray and UV photoelectron spectroscopy before and after heat treatment in vacuum and oxygen atmosphere. The results on ex situ prepared ceramic specimens were shown to be comparable to those of in situ deposited-measured thin films in terms of core levels, Fermi levels and ionization potentials. This suggests a viable path for rapid synthesis and screening of surface electronic-defect properties for other transparent conducting oxides (TCO) materials. A strong correlation exists between the surface electronic-defect structure of In2O3-based TCOs and their underlying electronic-defect structure, owing to the unique crystal-defect properties of the bixbyite structure. This leads to formation of a chemical depletion at the surface and the formation of a peroxide surface species for higher preparation temperatures. The results are discussed with respect to the use of ITO as hole injection electrode in organic light emitting devices.