Lee, Hyo-Sang Lee, Joong Suk Cho, Sanghyeok Kim, Hyunjung Kwak, Kyung-Won Yoon, Youngwoon Son, Seon Kyoung Kim, Honggon Ko, Min Jae Lee, Doh-Kwon Kim, Jin Young Park, Sungnam Choi, Dong Hoon Oh, Se Young Cho, Jeong Ho Kim, BongSoo 2024-01-20T13:30:26Z 2024-01-20T13:30:26Z 2021-09-05 2012-12-20 1932-7447 https://pubs.kist.re.kr/handle/201004/128537 We report high-performance of ambipolar organic field-effect transistors (FETs) based on the low band gap copolymers of pDPPT2NAP-HD and pDPPT2NAP-OD. The polymers are composed of electron-rich 2,6-di(thienyl)naphthalene (T2NAP) and electron-deficient diketopyrrolopyrrole (DPP) units with branched alkyl chains of 2-hexyldecyl (HD) or 2-octyldodecyl (OD). The polymers were polymerized via Suzuki coupling, yielding optical band gaps of similar to 1.4 eV. In the transistor performance test, we observed good ambipolar transport behavior in both polymer films, and pDPPT2NAP-OD displayed hole and electron mobilities 1 order of magnitude higher than the corresponding properties of pDPPT2NAP-HD. Thermal annealing of the polymer films increased the carrier mobilities. Annealing at 150 degrees C provided optimal conditions yielding saturated film crystallinity and maximized carrier mobility. The highest hole and electron mobilities achieved in these polymers were 1.3 and 0.1 cm(2)/(V s), respectively, obtained from pDPPT2NAP-OD. The polymer structure and thermal annealing affected the carrier mobility, and this effect was investigated by fully characterizing the polymer films by grazing incidence X-ray diffraction (GIXD), atomic force microscopy (AFM), and transmission electron microscopy (TEM) experiments. The GLXD data revealed that both polymers formed highly crystalline films with edge-on orientation. pDPPT2NAP-OD, which included longer alkyl chains, showed a higher tendency to form long-range order among the polymer chains. Thermal annealing up to 150 degrees C improved the polymer film crystallinity and promoted the formation of longer-range lamellar structures. AFM and TEM images of the films were consistent with the GI-XD data. Theoretical calculations of the polymer structures provided a rationale for the relationship between the torsional angle between aromatic rings and the carrier mobility. From the intensive electrical measurements and full characterizations, we find that the chemical structure of polymer backbone and side alkyl chain has a profound effect on film crystallinity, morphology, and transistor properties. English American Chemical Society HIGH-MOBILITY N-CHANNEL SEMICONDUCTING POLYMERS HOLE MOBILITY ELECTRON DESIGN STABILITY TRANSPORT CIRCUITS PACKING Crystallinity-Controlled Naphthalene-alt-diketopyrrolopyrrole Copolymers for High-Performance Ambipolar Field Effect Transistors Article 10.1021/jp309213h 1 The Journal of Physical Chemistry C, v.116, no.50, pp.26204 - 26213 The Journal of Physical Chemistry C 116 50 26204 26213 scie scopus 000312519600012 2-s2.0-84871544485 Chemistry, Physical Nanoscience & Nanotechnology Materials Science, Multidisciplinary Chemistry Science & Technology - Other Topics Materials Science Article HIGH-MOBILITY N-CHANNEL SEMICONDUCTING POLYMERS HOLE MOBILITY ELECTRON DESIGN STABILITY TRANSPORT CIRCUITS PACKING Polymer field-effect transistors Low band gap polymers Ambipolar transistors Crystalline structure High carrier mobility