| Summary: | 碩士 === 國立清華大學 === 電子工程研究所 === 92 === Organic light-emitting diodes (OLEDs) are the most potential technology for flat panel display. OLEDs possess many advantages, such as low operation voltage, low power consumption, self-emissive source, high brightness, short response time, good contrast ratio, large viewing angle, thin and lightweight, visibility at all lighting levels, and flexibility. OLEDs are therefore promising technology in the next-generation flat panel display. Among various forms of OLEDs, active-matrix OLED, which meets the requirements of high data rate and high resolution, is the most important one.
In this thesis, we use organic thin-film transistor (OTFT) and organic light-emitting diode (OLED) as active devices, in order to fabricate organic active-matrix pixel. We use polymer semiconductor material P3HT to replace conventional hole transport layer, PEDOT:PSS, so that only one processing step is required. With such one processing step, the polymer semiconductor material P3HT for both active layer of OTFT and hole transport layer of PLED are prepared. By this way, we could reduce the processing steps for active-matrix driving PLED.
Firstly, we fabricate simple active-matrix pixel, with one OTFT and one PLED. But storage capacitors are not provided, and no memory effect is supplied. For the active-matrix pixel area 100μm x 100μm, this device can supply maximum drain current 3.6μA for PLED, and PLED brightness can reach 490cd/m2 at the same time.
After successful fabrication of the simple active-matrix pixel, we turned to fabricate organic active-matrix pixel with memory effect. Such pixel contains one PLED, two OTFT, and one storage capacitor. This designed circuit can reduce driving current and increase the operation life-time of polymer electro-luminescence materials. We successfully demonstrated the integration of two OTFT and storage capacitor on one substrate. In the pulse operation, 2T1C circuit can supply continuous output current, and let PLED sustaining brightness.
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