氧氣電漿處理對可橈式AZO/PI 界面黏著力改善之探討

Abstract

This study focuses on using oxygen plasma treatment to improve the adhesion between ODPA-BADB polyimide (PI) and aluminum-doped zinc oxide (AZO). The results from this research can be applied to flexible devices such as FOLED or flexible solar cell. A new ODPA-BADB polyimide was synthesized in this research group by using two monomers 4,4-oxydiphthalic anhydride (ODPA) and bis(4-aminophenyl)-1,4-diisopropylbenzene (BADB). ODPA-BADB polyimide film possesses high glass transition temperature (Tg = 252 oC) and high transmitance (90%). The effect of oxygen plasma treatment conditions (power and treatment time) on the adhesion characteristics of polyimide surface and AZO/PI interface were investigated by means of four-point bending test method, contact angle measurement, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). The effect of oxygen plasma treatment to on electrical properties and surface energies of AZO films also investigated by four-point probe and X-ray diffraction (XRD). The results showed that both the surface energy of PI and adhesion energy of AZO/PI increased significantly after PI was treated by oxygen plasma. Adhesion energy increased with the increasing of RF treatment power, but the surface energy of PI increased only slightly with increasing RF power and treatment time. The enhanced adhesion at AZO/PI interface could be attributed to increased roughness, the formation of the new polar group such as C-OH and increased percentage of oxygenated, polar groups such as C-O and C=O on PI surface. The surface of AZO remained very smooth when deposited onto oxygen plasma-modified polyimide films. However, the resistivity of AZO film was degraded when the polyimide film was treated by oxygen plasma. The increased resistivity of AZO films can be attributed to the increased surface roughness of polyimide by plasma modification and possibly the incorporation of C and O impurities during sputtering deposition.

This study focuses on using oxygen plasma treatment to improve the adhesion between ODPA-BADB polyimide (PI) and aluminum-doped zinc oxide (AZO). The results from this research can be applied to flexible devices such as FOLED or flexible solar cell. A new ODPA-BADB polyimide was synthesized in this research group by using two monomers 4,4-oxydiphthalic anhydride (ODPA) and bis(4-aminophenyl)-1,4-diisopropylbenzene (BADB). ODPA-BADB polyimide film possesses high glass transition temperature (Tg = 252 oC) and high transmitance (90%). The effect of oxygen plasma treatment conditions (power and treatment time) on the adhesion characteristics of polyimide surface and AZO/PI interface were investigated by means of four-point bending test method, contact angle measurement, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). The effect of oxygen plasma treatment to on electrical properties and surface energies of AZO films also investigated by four-point probe and X-ray diffraction (XRD). The results showed that both the surface energy of PI and adhesion energy of AZO/PI increased significantly after PI was treated by oxygen plasma. Adhesion energy increased with the increasing of RF treatment power, but the surface energy of PI increased only slightly with increasing RF power and treatment time. The enhanced adhesion at AZO/PI interface could be attributed to increased roughness, the formation of the new polar group such as C-OH and increased percentage of oxygenated, polar groups such as C-O and C=O on PI surface. The surface of AZO remained very smooth when deposited onto oxygen plasma-modified polyimide films. However, the resistivity of AZO film was degraded when the polyimide film was treated by oxygen plasma. The increased resistivity of AZO films can be attributed to the increased surface roughness of polyimide by plasma modification and possibly the incorporation of C and O impurities during sputtering deposition.