The flexible display and the application of Roll-To-Roll process is difficult because high temperature process of a-Si;H TFT and poly-Si TFT limited the use of plastic substrate. We proposed AMOLED using Pentacene TFT (OTFT) to fabricate flexible display. The first stage for OTFT application to OLED, we analyzed OTFT as driving device of OLED. The process performed on glass and plastic (PET) substrate that is coated ITO and PVP is used for gate insulator. The field effect mobility of the fabricated OTFT is 0.1~0.3cm2/V•sec and Ion/Ioff current ratio is 103~105. OLED is fabricated with two stories structure of TPD and Alq3, and we can observe the light at 5V by the naked eye. The wavelength of observed lights is 530nm ~550nm. We can confirm the driving of OLED due to OTFT using Test panel and observe OLED control by gate voltage of OTFT. Also, we verify designed structure and process, and make a demonstration fabricating 64 by 64 backplane based on Test panel.
In this paper we developed an optimized process conditions of poly(4-vinylphenol) (PVP) as an organic gate compatible to polyethylene terephthalate(PET) substrate by varying the density of each component of PVP gate and also baking temperature. Pentacene TFTs were fabricated by the above obtained process and the performance was examined to find out the mobility of 0.7±0.2 cm2/V·sec and on/off current ratio of 106 and sub-threshold slope of 0.27V/dec, which can be applicable to drive an organic LED. In addition the inverters made on PET substrate provided the gain of 9 and exhibited the minor hysteresis which means the low interface states.