ITO薄膜的光学和电学性质及其应用

Electrical and Optical Properties and Applications of In_2O_3:Sn (ITO) Films

介绍了氧化铟锡 (ITO)薄膜的光学和电学性质及应用。优化的ITO薄膜有立方铁锰矿结构。掺杂的Sn替代In2 O3 晶格上的In原子 ,每个Sn原子可以看作给导带提供一个自由电子。ITO薄膜载流子浓度为～ 10 2 0 cm-3 ,电阻率为～ 10 -4Ωcm ,是高度简并半导体 ,其能带为抛物线型结构。由于Burstein -Moss效应 ,光学能隙加宽。除了紫外带间吸收和远红外的声子吸收 ,Drude理论与ITO的介电常数实际值符合得很好 ,说明自由电子对ITO薄膜的光学性质有决定性作用。

The electrical and optical properties and the applications of In 2O 3:Sn (ITO) films are introduced. The optimized films have a C-type rare-earth oxide structure. Sn acts as a cationic dopant in the In2O3 lattice and substitutes the indium. Each Sn atom can be taken to contribute one electron for the conduction band. The free electron density is ～10 20 cm -3 . The dc resistivity is ～10 -4 Ωcm and the corresponding mobility ～30 cm 2/Vs. The energy bands are assumed to be parabolic structure. The Burstein-Moss effect results in band-gap widening. Except the interband absorption in the ultraviolet and the phonon absorption in the far infrared, the main features of the dielectric functions for ITO are consistent with the Drude theory, and hence it is evident the that free electrons play a crucial role for optical properties. The unique electrical and optical properties of ITO films make them find wildly increasing applications.