Polymer Photovoltaics – Techniques for flexible device and multilayer architecture construction

• Main Authors: Zhong-Yo, 何忠祐
• Other Authors: 何國川
• Format: Others
• Language: en_US
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/41685812019244638223

碩士 === 國立臺灣大學 === 高分子科學與工程學研究所 === 96 === From the engineering point of view, polymer photovoltaics or light emitting diodes gain their advantages over inorganic optoelectronics in the utilization of flexible substrate. On the other hand, efficiency is always the major demand for commercial application. Instead of pursuing device treatment methods and new materials with higher device performance in the field of organic optoelectronics, in this thesis, we devoted ourselves to flexible photovoltaics and new architectures for improving device performance. In the first part of our work, flexible photovoltaics based on conventional P3HT:PCBM bulk heterojunction system were fabricated on PET/ITO substrate. To simplify the procedures, a back glass support was used for spin coater. Upon the optimization of the manufacture technique, efficiency more than 3% has been demonstrated for flexible photovoltaics. Furthermore, large area, flexible device with short current ~40 mA and open circuit voltage ~1.2 V have been achieved. Secondly, film transfer technology through poly(di-methylsilane) (PDMS) for the fabrication of organic optoelectronic thin films has been demonstrated. The transfer process not only overcomes traditional problems on multilayered polymeric structure construction but furnishes the most convenient way for cascade devices fabrication. Through the process, it was found to be a function of the force exerted on PDMS and the target surface, as well as the temperature at which the transfer takes place completely and successfully. The surface morphology of the films grown on PDMS ensure larger surface roughness, thus creating more interface area and comparable conversion efficiency toward traditional process has been manifested. Additionally, benefited from residual free process, cascade structure with donor acceptor distribution control in photoactive layer is successfully demonstrated even higher device performance could be approached in the future. Furthermore, by controlling the surface properties of the stamp, different interaction of the PDMS toward each components on it was supposed to be an fruitful medium for self-organization of organic materials what was preferred for photonic and electronic properties of the organic optoelectronic thin films.