ITO薄膜的研究进展

ITO是锡掺杂氧化铟薄膜的简称,属于透明导电氧化物材料。常规沉积方法制备的ITO薄膜通常为非晶态或体心立方晶系晶体,为n型半导体材料,其载流子为自由电子,主要来源于沉积过程中薄膜化学计量比偏离或阳离子掺杂形成的施主杂质。ITO薄膜是当前研究和使用最为广泛的透明导电氧化物薄膜材料,由于具有低电阻率、高可见光透过率、高红外反射率等独特物理特性而被大量应用于平板显示器、太阳能电池、发光二极管、气体传感器、飞机风挡玻璃除霜器等领域。此外,ITO薄膜对微波还具有高达85%的衰减作用,因而在电磁屏蔽等军用领域显示出巨大的潜在应用价值。过去几十年里,针对ITO薄膜的研究工作主要聚焦于薄膜的光电性能上。当前,伴随着ITO薄膜的应用范围在航空航天和军用武器装备等领域的拓展,ITO薄膜在恶劣力学环境中的使用日渐增多。因此,除光电性能外,ITO薄膜的力学性能也开始受到研究者越来越多的关注,人们对薄膜器件在各类恶劣使用环境中的稳定性及耐久性提出了更高的要求,这一要求使得对ITO薄膜力学性能的深入研究分析有了重要的理论及实际意义。本文综述了近年来ITO薄膜在微结构特性、能带结构、光电性能及力学性能等方面的研究进展,简略探讨了ITO薄膜的研究发展方向。

Research Progress of ITO Thin Films

ITO is the abbreviation of tin doped indium oxide thin film, which belongs to the group of transparent conducting oxide materials. ITO thin films fabricated by conventional deposition methods show amorphous or body-centered cubic crystal structure ordinarily, and perform as n-type semiconductors, their carriers deriving from the donor impurities caused by the deviation of stoichiometric ratio and cation doping during film deposition. ITO thin film is the most widely applied and investigated transparent conducting oxide thin film, thanking to their unique properties such as low resistivity, high transmittance within visible region, high reflectance within infrared region. ITO thin films have been extensively used in flat panel displays, solar cells, light emitting diodes, gas sensors and window shield defrosters of aircrafts. In addition, the attenuation of ITO thin film to microwave could be as high as 85%, which unfold its potential value in military applications such as electromagnetic shielding. During the last several decades, most researchers focused their attentions on optoelectrical properties of ITO thin films. Nowadays, with the applied extension of ITO thin film in aeronautic, astronautic and military weapons domains, the applied occasions of ITO thin film in hostile environment increase tremendously. Therefore, besides optoelectrical properties, the mechanical properties of ITO thin film attract more and more attentions from researchers, and higher requirements of stability and durability under hostile environment are raised. Thus, further investigations on mechanical properties are considered to show important significance theoretically and practically. This paper reviewed the current advance on microstructure properties, energy band structure, opto-electrical properties and mechanical properties of ITO thin films, and the dominant directions of the investigation of ITO thin films were briefly discussed.