Synthesis and Characterization of Poly(3-hexylthiophene) Derivatives for Optoelectronic Applications

• Main Authors: Yi-Jang Lee, 李易展
• Other Authors: Yu-Kai Han
• Format: Others
• Language: en_US
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/08240260233344854311

碩士 === 國立高雄應用科技大學 === 化學工程系碩士班 === 96 === The polymer photovoltaic cells have attracted much attention due to their possibilities of low-production cost, light-weight, flexible and easy manufacturing by solution process in recent years. Several laboratories have reported high-performance polymer photovoltaic cells using poly(3-hexylthiophene) (P3HT) as an electron donor and [6,6]-phenyl C61 butyric acid methyl ester (PCBM) as an electron acceptor. As a photo-active layer material in polymer photovoltaic cells: first, the conjugated polymers need effective absorption of visible light and the band-width of their absorption must be broad enough; second, it needs characteristics of both low band gap and high charge-separating (electron and hole) ability. Although the optical/electrical properties of active layer themselves are the most important one for the efficient charge generation and transport. Thus, two alternative copolymers: poly{(3-hexylthiophene)-alt-(3,4-ethylene- dioxythiophene)}(PT6EDOT-alt.) and poly{(3-hexylthiophene)-alt-(pyridine)}(PT6-Pys) were prepared. In addition, random copolymers (PT6EDOT-ran.) were copolymerized by oxidative method based on different ratios of 3-hexylthiophene and 3,4-ethylene- dioxythiophene units. However, to study in the effect of the regioregularity of poly(3-hexylthiophene) on the performances of polymer photovoltaic devices, three types of poly(3-hexylthiophene) (P3HTs) were used this work. To identify structure nuclear magnetic resonance (NMR) was used, physical properties via gel permeation chromatography (GPC), thermal stability properties via thermogravimetric analysis (TGA) and differential scanning calorimetry analysis (DSC). Optical properties, UV-visible absorption (UV-vis), fluorescence (PL), and photo-electron spectroscopy in air (PESA) spectra were compared with commercial regioregular HT-P3HT. In addition, surface morphologies and device properties were measured by atomic force microscope (AFM) and solar simulator system (SMU), respectively. The observed characteristics are sufficiently better to make these polymers highly promising for the polymer photovoltaic cell applications.