Cho, Kie Yong Kim, Hyun-Ji Xuan Huy Do Seo, Jin Young Hwang, Seung Sang Choi, Dong Hoon Baek, Kyung-Youl 2024-01-19T20:04:44Z 2024-01-19T20:04:44Z 2021-09-02 2019-04-12 0266-3538 https://pubs.kist.re.kr/handle/201004/120103 Development of new hole-transport layer (HTL) materials for organic photovoltaic (OPV) applications is one crucial issue to mitigate such limitations of low power efficiency, processibility, and stability derived from poly (3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) as a common HTL material. To this end, poly(3-hexylthiophene) (P3HT)-based diblock copolymers including the different ratios between polystyrene (PSty) or/and poly(neopentyl styrene sulfonate) (PNSS) as a second block segment were designed and then used for incorporating with single wall carbon nanotubes (SWCNTs) to form potentially self-dopable nanocomposites. The structure of fabricated P3HT-based diblock copolymer/SWCNT nanocomposites was examined by microscopic and spectroscopic characterizations, exhibiting a charge transfer behavior between P3HT and SWCNT, and growth of the P3HT crystalline phase along the SWCNT surface with a form of the conducting path. The acquired SWCNT nanocomposites exhibited good solubility and dispersion in various organic solvents including toluene, chlorobenzene, THF, chloroform, and DMF, which are good solvents for the PSty or/and PNSS neutral second block. The concept for the neutralized second block by protecting groups can prevent the poisoning ITO substrate by water contamination as shown in the conventional aqueous PEDOT-PSS solution. Notably, the PNSS constituent in the nanocomposite was merely acidified to give in-situ sulfonic acid groups in PSty by simple thermolysis process at 160 degrees C for 30 min after a solution process for fabrication of a thin film. The thermolysis step provided efficient doping of P3HT by PSS, in which the thiophene groups worked as Bronsted base are protonated by taking protons from sulfonic acid groups and then lead to a form of ionic bonds between cationic thiophene and anionic sulfonate groups. In addition, the formed ionic bonds in the nanocomposites led to an insoluble thin film, which has a good advantage for the further solvent process without substantial damages. The beneficial features of the conducting path along SWCNT and the efficient doping of P3HT by PSS in the acquired nanocomposites led to ca. 5-fold higher electrical conductivity (3.16 S cm(-1)) and similar work function (5.1 eV) in comparison to water contained commercial PEDOT:PSS (0.6 S cm(-1) and 5.0 eV, respectively). As such, the rationally designed potentially self-dopable SWCNT nanocomposites can be one of the promising alternatives beyond the commercial PEDOT: PSS HTL material. English ELSEVIER SCI LTD CARBON NANOTUBES CHARGE-TRANSFER SOLAR-CELLS POLYMER PERFORMANCE DISPERSION MORPHOLOGY EFFICIENT OXYGEN FILMS Potentially self-dopable poly(3-hexylthiophene) block copolymers/carbon nanotube nanocomposites for enhanced processibility and electrical properties Article 10.1016/j.compscitech.2019.02.021 1 COMPOSITES SCIENCE AND TECHNOLOGY, v.174, pp.149 - 157 COMPOSITES SCIENCE AND TECHNOLOGY 174 149 157 scie scopus 000469407500018 2-s2.0-85062153218 Materials Science, Composites Materials Science Article CARBON NANOTUBES CHARGE-TRANSFER SOLAR-CELLS POLYMER PERFORMANCE DISPERSION MORPHOLOGY EFFICIENT OXYGEN FILMS Carbon nanotubcs P3HT/SWCNT composites Self-doping Electrical conductivity Hole-transport layers