摘要
采用van der Pauw法、等离子振荡波长法和光谱拟合法等三种方法对IMO(In2 O3 ∶Mo)薄膜和ITO(In2 O3 ∶Sn)薄膜的载流子迁移率进行了测量和比较。结果表明 ,IMO薄膜的载流子迁移率高达 10 0cm2 V-1s-1以上 ,远超过已报导的其他掺杂透明导电氧化物 (TCO)薄膜的载流子迁移率 ;IMO薄膜的载流子有效质量约为电子静止质量的 0 35倍 ;IMO薄膜的高载流子迁移率主要是由于载流子受到的散射作用较弱所引起。这无法用通常的掺杂TCO薄膜的载流子散射理论来解释 ,为此引入复合效应进行分析。在ITO薄膜中 ,每形成一个电中性复合粒子 ,就会使两个掺杂的Sn4+ 失去贡献载流子的电活性 ;而在IMO薄膜中 ,即使一个掺杂Mo6+ 与晶格间隙中的一个O2 -结合成复合离子后 ,该复合离子仍然会贡献出一个载流子 ,故薄膜中形成的电中性复合粒子数目较少 ,从而导致价态差为 3的IMO薄膜中的电中性复合粒子对载流子的散射远低于价态差为 1的ITO薄膜 ,因此 。
Van-der-Pauw method, plasmatic wavelength method and optical spectra fitting method were used to measure and compare the carrier mobility of IMO (In2O3:Mo) ITO (In2O3:Sn). The results show that the mobility of IMO is over 100 cm2V-1s-1, which is much higher than those of other transparent conductive oxide (TCO) films. The effective mass m* of the carrier of IMO is about 0.35 m. The high mobility is mainly due to the weak scattering in IMO. It is contradictory to the normal carrier scattering theory of TCO films. The effect of complexes was adopted to analyze the amazingly high mobility. Two Sn4+ will not contribute carriers when every neutral complex is formed in ITO, however, Mo6+ will contribute one carrier even after it associates with one interstitial O2- in IMO. Since there are much fewer electrical neutral complexes in IMO than those in ITO, the mobility of IMO may be higher than that of ITO.
出处
《真空科学与技术》
EI
CSCD
北大核心
2002年第4期265-269,共5页
Vacuum Science and Technology
