Novel TiO2/Poly(3-hexylthiophene) Hybrids Prepared by the Use of 2-(Triethoxysilane)alkylthiophene as Interface Linker

• Main Authors: Hsu-Jan Cheng, 鄭旭然
• Other Authors: Leeyih Wang
• Format: Others
• Language: en_US
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/95626113617678448501

碩士 === 國立臺灣大學 === 高分子科學與工程學研究所 === 93 === An electron donor (D)/electron acceptor (A) heterojunction was fabricated by depositing conjugated polymers with the aid of a layer of D-A linker on the surface of TiO2. The use of a D-A linker between TiO2 and the conducting polymer enables the formation of a strongly bonded composite, enhancing the efficiency of electron transfer between the donor and the acceptor. This study demonstrates a route for synthesizing novel hybrid materials of poly(3-hexylthiophene)/D-A linker/TiO2. The chemical structure of the molecular linker, which was used to connect chemically organic and inorganic phases, was designed with three main parts - a triethoxysilane group, an alkyl spacer and polymerizable thiophene ring. After the self-assembled monolayers (SAMs) of the linker were formed on the TiO2 surface, the terminal thiophene ring in the linker was used to initiate electro-chemically the growth of poly(3-hexylthiophene) chains electro-chemically for fabricating the novel composite of poly(3-hexylthiophene)/D-A linker/TiO2. The prepared self-assembled monolayers were characterized by contact angle, TGA, AFM and XPS measurements. Both the AFM and the GPC methods were employed to examine the surface morphology of the composites. The efficiency of the photoluminescence (PL) quenching in blends of electron donors and electron acceptors is one of the most important factors that govern the energy conversion efficiency of a photovoltaic cell. PL studies of these new hybrid materials indicate that the quenching efficiency increased as the alkyl spacer length in the D-A linker decreased, perhaps because the surface resistance increases with the length of the alkyl chain. Notably, the presence of the D-A linker between P3HT and TiO2 effectively increases the quenching efficiency of the photoluminescence above that of neat P3HT films on TiO2.