ITO薄膜的电阻并联效应研究

Research on Resistance Parallel Effect of ITO Films

摘要:

采用电子束蒸发镀膜方法在K9玻璃基底上分别镀制了ITO/SiO₂/ITO,ITO/Ti₂O₃/ITO和ITO/MgF₂/ITO结构的多层薄膜,用四探针方块电阻仪测量薄膜表面的方块电阻,用原子力显微镜观测样品的表面微观形貌。结果显示,当ITO薄膜的粗糙度较大且介质薄膜的物理厚度小于100nm时,各层ITO薄膜之间通过山峰状的凸起结构相连通,导致样片表面的方块电阻测量值与各层ITO薄膜电阻的并联值相当。这表明,当ITO薄膜的粗糙度较大且介质薄膜厚度较小时,各层ITO薄膜表现出电阻并联效应。利用多层ITO薄膜的电阻并联效应设计并制备了450～1200nm超宽光谱透明导电薄膜,用四探针方块电阻仪测量了试验样片的表面方块电阻,用紫外-可见-近红外分光光度计测试了样片的光谱透射率。结果显示,在相同表面方块电阻条件下,相比于单层ITO薄膜,利用ITO薄膜电阻并联效应所制备的多层透明导电薄膜具有更高的光谱透射率。

Abstract:

Multilayer films with the structures of ITO/SiO₂/ITO, ITO/Ti₂O₃/ITO and ITO/MgF₂/ITO were coated on the K9 glass substrate by electron beam evaporation coating method. The square resistance on the surface of the films was measured by four-probe square resister and the surface microstructure of the samples was observed by atomic force microscope (AFM). The results show that when the roughness of ITO film is large and the physical thickness of the medium film is less than 100nm, each layer of ITO films is connected through some bump structures like mountains, resulting in that the measured square resistance of the surface of the sample film is almost the same as the square resistance in parallel of each layer of ITO films. This indicates that when ITO film roughness is large and medium film thickness is small, it will cause the resistance of each ITO film to be in parallel. The 450~1200nm ultra-wide spectrum transparent conductive film was designed and prepared by using the square resistance parallel effect of multilayer ITO films. The surface square resistance of the test sample was measured with a four-probe square resistor and the spectrum transmittance of the sample was measured with a spectrophotometer. The results show that the multilayer transparent conductive film prepared by the square parallel resistance effect of ITO films has a higher spectral transmittance than the single layer ITO film under the same surface square resistance.