Applications and stability of organic semiconductor devices by solution process

• Main Authors: Chen, Chao-Hsuan, 陳兆軒
• Other Authors: Zan, Hsiao-Wen
• Format: Others
• Language: en_US
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/ssz86f

博士 === 國立交通大學 === 光電工程研究所 === 107 === In this dissertation, different types of organic semiconductor devices are fabricated by solution process, including space-Charge-Limited Transistor (SCLT), organic photo detector (OPD), polymer solar cell (PSC) and OLED-gas sensor. Due to the material properties, organic semiconductor devices usually have a significant deterioration in characteristics after a long period of operation, it will unfavorable for commercial applications. Therefore, we used different methods to improve device characteristics for different semiconductor devices and improved their stability under long-term operation. The first part discussed SCLT (Chapter 3). The mesh structure of nanoscale base metal was coated with insulating material by using a unique contact coating process technology. The coating shape was controlled by adjusting pulling speed and solution concentration, the purpose of suppressing the leakage current from base was successfully achieved. In the second part, we solved the light guide effect of the encapsulation layer in traditional OPD by developing the proximity sensor with air stable property (Chapter 4). The finger-type structure of bottom electrode metal was vertically integrated with the light source, it further achieved the purpose of sensing system miniaturization. The sensing ability was sub-centimeter level. In addition, the experiment also fabricated this structure on a polyethylene naphthalate (PEN) substrate, the distance sensing capability was maintained after 1000 times bending. In the third part (Chapter 5), the interfacial layer between the electrode and the semiconductor layer was inserted to solve the PSC’s short lifetime, whether it is in the normal or the inverted structure. The interfacial layer was coated by solution process and traced the devices for a long time in a high temperature (80 °C) environment. The half-lifetime of normal structured PSCs had increased from one hour to more than 100 hours, while the inverted structural PSCs had more than 6000 hours half-lifetime. This work greatly improved the stability of PSCs in long-term high temperature environment. The fourth part (Chapter 6) showed the organic light-emitting diode devices with gas sensing capability. The gas molecular penetrated into the sensing layer of devices for detection by an extremely thin metal electrode (less than 10 nanometers), and the sensing sensitivity was up to the ppm level.