| Summary: | 碩士 === 南台科技大學 === 電機工程系 === 91 === In this study, the DC magnetron sputtering was employed to fabricate indium tin oxide (ITO) films for organic light-emitting diode (OLED) application. Process parameters, such as pressure, power and substrate temperature, were varied to observe then effects on the resistivity, transparency and surface roughtness of the ITO films. The ITO films were thermal annealed at 300oC in high vacuum to realize the possible factors that would affect the ITO film properties after the thermal cycle. Ni-doped ITO was co-sputtered on top of the un-doped ITO film using RF and DC power respecting for Ni & ITO. During the co-sputtering various parameters such as power, deposition time and gas flow were changed to observe the effect of the resistivity, transparency, dopant concentration of the Ni dopped ITO with Ni. Results showed that the without Ni doping best ITO film characteristics were achieved under an optimized sputtering condition of 120oC, 300W and 3.2 mtorr. ITO sheet resistivity as low as 2.4E-4Ω-cm and optical transparency up to 91.7%, Have been obtained next paragraph double hetrojunction OLED devices with the structure of Al(50nm) /Alq3(35nm)/NPB(20nm)/ITO(200nm) /glass were fabricated using the optimized ITO film with and without Ni doping as the anode. Devices with an turn-on voltage of 12V for undoped ITO samples. The second part experimental results showed that the best ITO film characteristics were achieved under an optimized sputtering condition of 300W and 90sec the ITO sheet resistivity as low as 2.0E-4Ω-cm, optical transparency up to 90%, can be achieved and with an turn-on voltage of 6.5V for Ni-doped ITO samples were observed.
With Ni doping, pat this in the end of paragh 1. with Ni-doping in ITO the maximum luminescence of the OLED devices was 2611 cd/m2; the luminescent efficiency was 1.093 lm/W; and the power consumption of OLED could effectively reduced to 0.941 lm/W.
From the results, with Ni-doped ITO films the OLED devices can perform better turn on voltage, luminescence efficiency and power consumption mainly due to the potential barrier reduction at the ITO/NPB interface attribwted by the adding of Ni in ITO.
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