Construction of Stretchable Polymer Semiconductor via Siloxane Side Chain Engineering

Longzhen Qiu 한국고분자학회 2022 한국고분자학회 학술대회 연구논문 초록집 Vol.47 No.1

Organic Thin-film Transistors Based on Polythiophene Nanowires Embedded in Insulating Polymer

Qiu, Longzhen,Lee, Wi Hyoung,Wang, Xiaohong,Kim, Jong Soo,Lim, Jung Ah,Kwak, Donghoon,Lee, Shichoon,Cho, Kilwon WILEY-VCH Verlag 2009 Advanced Materials Vol.21 No.13

<B>Graphic Abstract</B> <P>Blending poly(3-hexylthiophene) (P3HT) and amorphous polystyrene (PS) using a marginal solvent (CH<SUB>2</SUB>Cl<SUB>2</SUB>) with temperature-dependent solubility allows a reduction of the semiconductor content to as low as 3 wt% without considerable degradation of the field-effect electronic properties. Morphological and structural studies reveal that the P3HT molecules in these blends form highly crystalline, interconnected nanofibrillar networks. <img src='wiley_img/09359648-2009-21-13-ADMA200802880-content.gif' alt='wiley_img/09359648-2009-21-13-ADMA200802880-content'> </P>

Enhanced Performance of Organic Transistor Sensors using Porous Films

Longzhen Qiu,Lijun Zhang,Guobing Zhang,Shaohua Wu,Qinghe Wang 한국고분자학회 2017 한국고분자학회 학술대회 연구논문 초록집 Vol.42 No.2

Inkjet‐Printed Single‐Droplet Organic Transistors Based on Semiconductor Nanowires Embedded in Insulating Polymers

Lim, Jung Ah,Kim, Joo‐,Hyun,Qiu, Longzhen,Lee, Wi Hyoung,Lee, Hwa Sung,Kwak, Donghoon,Cho, Kilwon WILEY‐VCH Verlag 2010 Advanced functional materials Vol.20 No.19

<P><B>Abstract</B></P><P>Fabrication of organic field‐effect transistors (OFETs) using a high‐throughput printing process has garnered tremendous interest for realizing low‐cost and large‐area flexible electronic devices. Printing of organic semiconductors for active layer of transistor is one of the most critical steps for achieving this goal. The charge carrier transport behavior in this layer, dictated by the crystalline microstructure and molecular orientations of the organic semiconductor, determines the transistor performance. Here, it is demonstrated that an inkjet‐printed single‐droplet of a semiconducting/insulating polymer blend holds substantial promise as a means for implementing direct‐write fabrication of organic transistors. Control of the solubility of the semiconducting component in a blend solution can yield an inkjet‐printed single‐droplet blend film characterized by a semiconductor nanowire network embedded in an insulating polymer matrix. The inkjet‐printed blend films having this unique structure provide effective pathways for charge carrier transport through semiconductor nanowires, as well as significantly improve the on‐off current ratio and the environmental stability of the printed transistors.</P>

Polymer blends with semiconducting nanowires for organic electronics

Jo, Sae Byeok,Lee, Wi Hyoung,Qiu, Longzhen,Cho, Kilwon The Royal Society of Chemistry 2012 Journal of materials chemistry Vol.22 No.10

<P>This article reviews the recent advances in organic electronics based on polymer blends with one-dimensional (1D) nanowires (NWs) of π-conjugated polymers. Self-assembled polymer semiconducting NWs are fascinating building blocks for their directional extension of inter- and intramolecular π-conjugation. This extensive conjugation provides unique electrical and optical properties that benefit applications in organic electronic devices. Outstanding performances are particularly expected from blending these NWs with insulating polymers or semiconducting molecules. Several representative reports describing NWs prepared from semiconducting/insulating polymer blends, conjugated block copolymers, or electrospinning for use as high-performance organic thin-film transistors (OTFTs) are discussed. The concepts of phase-separation behavior and the growth of crystalline NWs from multi-phase blend solutions are also illustrated. Research into the solubility-induced formation of NWs from semiconducting polymer/n-type small molecule blends for high-efficiency organic photovoltaic solar cells (OPVs) is introduced. In addition, the effects of the chemical properties of conjugated polymers on the optical and electrical properties of NWs and the use of ordered NW structures in OPVs are summarized. This critical review provides insights and a new perspective on the optimization of blend morphologies, which consequently enhances the performance of organic electronic devices.</P> <P>Graphic Abstract</P><P>Recent advances and fundamentals in organic electronic devices based on polymer blends with one-dimensional nanowires of π-conjugated polymers are reviewed. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2jm16059e'> </P>

Fused Heptacyclic-Based Acceptor-Donor-Acceptor Small Molecules: N-Substitution toward High-Performance Solution-Processable Field-Effect Transistors

Zhang, Guobing,Zhao, Yao,Kang, Boseok,Park, Sangsik,Ruan, Jiufu,Lu, Hongbo,Qiu, Longzhen,Ding, Yunsheng,Cho, Kilwon American Chemical Society 2019 Chemistry of materials Vol.31 No.6

<P>Although various donor-acceptor (D-A) small molecules with high power conversion efficiency have been reported, D-A small molecules with high field-effect mobility are still rare. In this work, two new A-D-A small molecules with a rigid indacenodithieno[3,2-<I>b</I>]thiophene (<B>IDTT</B>) moiety as the central core and both ends capped with strong electron-withdrawing indole-2,3-dione (<B>IDD</B>) and N-substituted pyrrolo[2,3-<I>b</I>]pyridine-2,3-dione (<B>IDD-N</B>) were synthesized and characterized for applications in solution-processable organic field-effect transistors (OFETs). A N atom was introduced to the <B>IDD</B> units to enhance the planarity and structural ordering by noncovalent interactions, leading to a dramatic effect on the small molecule. The unsubstituted small molecule (<B>IDTT-IDD</B>) did not show any field-effect performance, whereas an encouraging hole mobility of 7.7 cm<SUP>2</SUP> V<SUP>-1</SUP> s<SUP>-1</SUP> with an average mobility of 6.1 cm<SUP>2</SUP> V<SUP>-1</SUP> s<SUP>-1</SUP> was obtained for solution-processable OFETs based on the N-substituted one (<B>IDTT-IDD-N</B>). This work provided a simple and effective molecular strategy for the design of D-A small molecules for high-performance solution-processable OFETs.</P> [FIG OMISSION]</BR>

Synthesis and characterization of thieno-isoindigo derivative-based near-infrared conjugated polymer for ambipolar field-effect transistors and photothermal conversion

Zhang, Guobing,Dai, Yanrong,Wang, Dong,Liu, Yu,Lu, Hongbo,Qiu, Longzhen,Cho, Kilwon Elsevier 2017 Dyes and pigments Vol.147 No.-

<P><B>Abstract</B></P> <P>A new thieno-isoindigo derivative, (3<I>E</I>,7<I>E</I>)-3,7-bis(4-(2-decyltetradecyl)-4<I>H</I>-thieno[3,2-<I>b</I>]pyrrole-5,6-dione)-5,7-dihydropyrrolo[2,3-<I>f</I>]indole-2,6(1<I>H</I>,3<I>H</I>)-dione (<B>BTPDI</B>), was designed and synthesized. A donor−acceptor conjugated polymer (<B>PBTPDI-TT</B>) was also synthesized with this new unit as the acceptor and thieno[3,2-<I>b</I>]thiophene as the donor. The microstructure, photophysical, electrochemical, field-effect properties and photothermal performances were investigated. The polymer showed a broad absorption spectrum that spanned across the near-infrared (NIR) region (780–1300 nm), with a very low bandgap (∼0.95 eV), deep lowest unoccupied molecular orbital, and suitable highest occupied molecular orbital levels. As a result, the polymer-based organic field-effect transistors showed highly balanced hole and electron transport characteristics with a hole mobility of 0.027 cm<SUP>2</SUP> V<SUP>−1</SUP>s<SUP>−1</SUP> and an electron mobility of 0.022 cm<SUP>2</SUP> V<SUP>−1</SUP>s<SUP>−1</SUP>. The polymer nanoparticles showed good reusability under NIR (980 nm) irradiation and could also effectively convert NIR light to heat at an excellent efficiency of 20.3%.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A new thieno-isoindigo derivative dye and its polymer were designed and synthesized. </LI> <LI> The polymer showed ultra broad absorption spectra that spanned across the near-infrared region and remarkably low bandgap. </LI> <LI> The new polymer showed highly balanced hole and electron transport characteristics. </LI> <LI> Polymer nanoparticles showed excellent photothermal conversion efficiency under 980 nm irradiation. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Tuning the Energy Levels of Aza-Heterocycle-Based Polymers for Long-Term <i>n</i>-Channel Bottom-Gate/Top-Contact Polymer Transistors

Ma, Suxiang,Zhang, Guobing,Wang, Feifei,Dai, Yanrong,Lu, Hongbo,Qiu, Longzhen,Ding, Yunsheng,Cho, Kilwon American Chemical Society 2018 Macromolecules Vol.51 No.15

<P>Conjugated polymer-based organic thin film transistors (OTFTs) have received tremendous attention due to their potential applications. In addition to their high performances, air stability is also essential for application and another main property that OTFTs have. In this paper, three aza-heterocycle (BABDF)-based polymers were designed and synthesized using strong donor thiophene-vinylene-thiophene (TVT), weak donor thiophene-cyanovinylene-thiophene (TCNT), and weak acceptor dithiazole (TZ) as co-units. The lowest unoccupied molecular orbital (LUMO)/highest occupied molecular orbital (HOMO) energy levels were effectively lowered by introducing TCNT and TZ units, especially for PBABDF-TZ, for which the too much deep LUMO/HOMO energy levels of −4.28/-6.06 eV were obtained. These levels are low enough for air-stable electron transport and large enough for the hole injection barriers in OTFTs. Consequently, the unencapsulated bottom-gate/top-contact (BG/TC) devices exhibited unipolar electron transport under air conditions. Furthermore, these devices had high air stability and maintained unipolar electron transport with a mobility of up to 0.01 cm<SUP>2</SUP> V<SUP>-1</SUP> s<SUP>-1</SUP> during the one-year characterization period. Very low LUMO and HOMO levels were necessary for electron transport and the hole barriers, respectively, and both were important for long-term, air-stable <I>n</I>-channel polymer transistors.</P> [FIG OMISSION]</BR>

An ABA triblock copolymer strategy for intrinsically stretchable semiconductors

Peng, Rui,Pang, Bo,Hu, Daqing,Chen, Mengjie,Zhang, Guobing,Wang, Xianghua,Lu, Hongbo,Cho, Kilwon,Qiu, Longzhen The Royal Society of Chemistry 2015 Journal of Materials Chemistry C Vol.3 No.15

<▼1><P>A novel semiconductor–rubber–semiconductor triblock copolymer has been designed and prepared according to the principle of thermoplastic elastomers (TPEs). It behaves as a TPE and exhibits good electrical properties.</P></▼1><▼2><P>A novel semiconductor–rubber–semiconductor (P3HT–PMA–P3HT) triblock copolymer has been designed and prepared according to the principle of thermoplastic elastomers. It behaves as a thermoplastic elastomer with a Young's modulus (<I>E</I>) of 6 MPa for an elongation at break of 140% and exhibits good electrical properties with a carrier mobility of 9 × 10<SUP>−4</SUP> cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP>. This novel semiconductor may play an important role in low-cost and large-area stretchable electronics.</P></▼2>

Chirality detection of amino acid enantiomers by organic electrochemical transistor

Zhang, Lijun,Wang, Guiheng,Xiong, Can,Zheng, Lei,He, Jianbo,Ding, Yunsheng,Lu, Hongbo,Zhang, Guobing,Cho, Kilwon,Qiu, Longzhen Elsevier 2018 Biosensors & bioelectronics Vol.105 No.-

<P><B>Abstract</B></P> <P>Chiral recognition of α-amino acids is attracting increasing interest due to the importance of α-amino acids in protein metabolism as well as in food products and pharmaceuticals. Organic electrochemical transistors (OECTs) with gate electrodes modified with molecularly imprinted polymer (MIP) films were fabricated and successfully used as highly selective and sensitive chiral recognition biosensors for <SMALL>D/L</SMALL>-tryptophan (<SMALL>D</SMALL> <SMALL>/</SMALL> <SMALL>L</SMALL>-Trp) and <SMALL>D/L</SMALL>-tyrosine (<SMALL>D</SMALL> <SMALL>/</SMALL> <SMALL>L</SMALL>-Tyr). The MIP films, which can specifically recognize and has an electrocatalytic effect on the oxidation of Trp and Tyr, together with the amplification function of an OECT, provide a highly sensitive and selective OECT biosensor. The sensor showed a linear response range for <SMALL>L</SMALL>-Trp and <SMALL>L</SMALL>-Tyr from 300 nM to 10 μM with a sensitivity of 3.19 and 3.64 μA/μM, respectivity. And the detection limit for <SMALL>L</SMALL>-Trp and <SMALL>L</SMALL>-Tyr is of 2 nM and 30 nM (S/N > 3). The selectivity factors of <SMALL>L</SMALL>-Trp, <SMALL>D</SMALL>-Trp, <SMALL>L</SMALL>-Tyr and <SMALL>D</SMALL>-Tyr to their enantiomers are 11.6, 3.5, 14.5 and 2.6, respectively. This method can pave the way for widespread applications of OECT-based sensors in chiral material identification.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An novel chiral recognition MIP-OECT sensor was developed. </LI> <LI> The MIP films showed good performance of selective and electro-catalytic oxidation for Trp and Tyr. </LI> <LI> The MIP films together with the amplification function of an OECT afforded a highly sensitive, selective sensor for chirality detection of amino acid enantiomers. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>