Investigation of interfaces between indium tin oxide and hole injection layer in organic light emitting diode

• Main Authors: Polo, 林信宏
• Other Authors: 尤建華
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/79930162832515657908

碩士 === 長庚大學 === 化工與材料工程研究所 === 93 === In this investigation, ITO substrates have been chemically treated with 20% H3PO4 and HNO3 solution. The differences between as-received ITO and CuPc and chemically treated-ITO and CuPc interfaces were observed to discuss the influences of different interface in OLEDs and expect to enhance the performances of OLEDs by improving the interfaces between ITO and CuPc. To observe the different surface morphology between as-received and chemically treated ITO, we have utilized techniques as SEM, AFM, and XRD. After the surface treatment, it is discovered that the ITO surface is decomposed by acid solution and make both rms and crystallization increase. According to the UV-Vis and four point probe measurement, the transparency of ITO was depended on the composition of ITO, and the surface treatment does not influence dramatically the transparency and sheet resistance. XPS and UPS have been employed to observe surface bonding condition and the change in work function of as-received and chemically- treated ITOs. The M-OH bonding and metal complex are formed on the ITO surface after the surface treatment. A better interface is obtained between ITO and CuPc when CuPc was evaporated on a chemically- treated ITO substrate. According to a better interface between CuPc and ITO, even if the worse performances of chemically-treated ITO in Rms and WF, but the performances of OLEDs which fabricated with chemically treated ITO still better.