Synthesis, Morphology, and Properties of Poly(3‐hexylthiophene)‐block‐Poly(vinylphenyl oxadiazole) Donor–Acceptor Rod–Coil Block Copolymers and Their Memory Device Applications

Novel donor–acceptor rod–coil diblock copolymers of regioregular poly(3‐hexylthiophene) (P3HT)‐block‐poly(2‐phenyl‐5‐(4‐vinylphenyl)‐1,3,4‐oxadiaz‐ole) (POXD) are successfully synthesized by the combination of a modified Grignard metathesis reaction (GRIM) and atom transfer radical polymerization (ATRP). The effects of the block ratios of the P3HT donor and POXD pendant acceptor blocks on the morphology, field effect transistor mobility, and memory device characteristics are explored. The TEM, SAXS, WAXS, and AFM results suggest that the coil block fraction significantly affects the chain packing of the P3HT block and depresses its crystallinity. The optical absorption spectra indicate that the intramolecular charge transfer between the main chain P3HT donor and the side chain POXD acceptor is relatively weak and the level of order of P3HT chains is reduced by the incorporation of the POXD acceptor. The field effect transistor (FET) hole mobility of the system exhibits a similar trend on the optical properties, which are also decreased with the reduced ordered P3HT crystallinity. The low‐lying highest occupied molecular orbital (HOMO) energy level (–6.08 eV) of POXD is employed as charge trap for the electrical switching memory devices. P3HT‐b‐POXD exhibits a non‐volatile bistable memory or insulator behavior depending on the P3HT/POXD block ratio and the resulting morphology. The ITO/P3HT44‐b‐POXD18/Al memory device shows a non‐volatile switching characteristic with negative differential resistance (NDR) effect due to the charge trapped POXD block. These experimental results provide the new strategies for the design of donor‐acceptor rod‐coil block copolymers for controlling morphology and physical properties as well as advanced memory device applications.

[1]  Gang Liu,et al.  Conjugated‐Polymer‐Functionalized Graphene Oxide: Synthesis and Nonvolatile Rewritable Memory Effect , 2010, Advanced materials.

[2]  S. Du,et al.  Improving the ON/OFF Ratio and Reversibility of Recording by Rational Structural Arrangement of Donor–Acceptor Molecules , 2010 .

[3]  R. Mezzenga,et al.  A New Supramolecular Route for Using Rod‐Coil Block Copolymers in Photovoltaic Applications , 2010, Advanced materials.

[4]  Wen‐Chang Chen,et al.  High Performance Volatile Polymeric Memory Devices Based on Novel Triphenylamine-based Polyimides Containing Mono- or Dual-Mediated Phenoxy Linkages , 2010 .

[5]  R. Segalman,et al.  Block Copolymers for Organic Optoelectronics , 2009 .

[6]  R. Segalman,et al.  The relationship between morphology and performance of donor–acceptor rod–coil block copolymer solar cells , 2009 .

[7]  Tomoya Higashihara,et al.  Living Anionic Polymerization of 4-Vinyltriphenylamine for Synthesis of Novel Block Copolymers Containing Low-Polydisperse Poly(4-vinyltriphenylamine) and Regioregular Poly(3-hexylthiophene) Segments , 2009 .

[8]  T. Satoh,et al.  Synthesis, thermomorphic characteristics, and fluorescent properties of poly[2,7-(9,9-dihexylfluorene)]-block-poly(N-isopropylacrylamide)-block-poly(N-hydroxyethylacrylamide) rod-coil-coil triblock copolymers , 2009 .

[9]  Jae Kwan Lee,et al.  Well-defined donor–acceptor rod–coil diblock copolymers based on P3HT containing C60: the morphology and role as a surfactant in bulk-heterojunction solar cells , 2009 .

[10]  En-Tang Kang,et al.  Electrical Conductance Tuning and Bistable Switching in Poly(N-vinylcarbazole)-Carbon Nanotube Composite Films. , 2009, ACS nano.

[11]  Cheng-Liang Liu,et al.  Synthesis and Memory Device Characteristics of New Sulfur Donor Containing Polyimides , 2009 .

[12]  Sridhar Rajaram,et al.  Effect of Addition of a Diblock Copolymer on Blend Morphology and Performance of Poly(3-hexylthiophene):Perylene Diimide Solar Cells , 2009 .

[13]  Jea-Gun Park,et al.  Multilevel nonvolatile small-molecule memory cell embedded with Ni nanocrystals surrounded by a NiO tunneling barrier. , 2009, Nano letters.

[14]  Dong Min Kim,et al.  Programmable digital memory devices based on nanoscale thin films of a thermally dimensionally stable polyimide , 2009, Nanotechnology.

[15]  R. Mezzenga,et al.  Crystalline Diblock Conjugated Copolymers: Synthesis, Self-Assembly, and Microphase Separation of Poly(3-butylthiophene)-b-poly(3-octylthiophene) , 2009 .

[16]  T. Emrick,et al.  Donor−Acceptor Poly(thiophene-block-perylene diimide) Copolymers: Synthesis and Solar Cell Fabrication , 2009 .

[17]  T. Kowalewski,et al.  Regioregular Poly(3-hexylthiophene) in a Novel Conducting Amphiphilic Block Copolymer. , 2009, Macromolecular rapid communications.

[18]  Koon Gee Neoh,et al.  Conductivity switching and electronic memory effect in polymers with pendant azobenzene chromophores. , 2009, ACS applied materials & interfaces.

[19]  R. Mezzenga,et al.  Poly[2,7-(9,9-dihexylfluorene)]-block-poly(2-vinylpyridine) Rod−Coil and Coil−Rod−Coil Block Copolymers: Synthesis, Morphology and Photophysical Properties in Methanol/THF Mixed Solvents , 2008 .

[20]  Koon Gee Neoh,et al.  Polymer electronic memories: Materials, devices and mechanisms , 2008 .

[21]  M. Thelakkat,et al.  Crystalline-crystalline donor-acceptor block copolymers. , 2008, Angewandte Chemie.

[22]  M. Urien,et al.  Poly(3-hexylthiophene) based block copolymers prepared by "click" chemistry , 2008 .

[23]  Panagiotis Dimitrakis,et al.  Electrical behavior of memory devices based on fluorene-containing organic thin films , 2008 .

[24]  Wen‐Chang Chen,et al.  Synthesis, structures and multifunctional sensory properties of poly[2,7-(9,9-dihexylfluorene)]-block-poly[2-(dimethylamino)ethyl methacrylate] rod-coil diblock copolymers , 2008 .

[25]  B. Olsen,et al.  Self-assembly of rod–coil block copolymers , 2008 .

[26]  Y. Lim,et al.  Rod–coil block molecules: their aqueous self-assembly and biomaterials applications , 2008 .

[27]  G. Hadziioannou,et al.  Design of a Linear Poly(3‐hexylthiophene)/Fullerene‐Based Donor‐Acceptor Rod‐Coil Block Copolymer , 2008 .

[28]  Koon Gee Neoh,et al.  Thermally stable polymer memory devices based on a π-conjugated triad , 2008 .

[29]  R. Mezzenga,et al.  Self-Assembly of Polypeptide/π-Conjugated Polymer/Polypeptide Triblock Copolymers in Rod−Rod−Rod and Coil−Rod−Coil Conformations , 2008 .

[30]  Sang-Hyun Hong,et al.  Novel Digital Nonvolatile Memory Devices Based on Semiconducting Polymer Thin Films , 2007 .

[31]  R. Mezzenga,et al.  Self-Assembly of Poly(diethylhexyloxy-p-phenylenevinylene)-b- poly(4-vinylpyridine) Rod−Coil Block Copolymer Systems , 2007 .

[32]  W. Su,et al.  Facile synthesis of well-defined block copolymers containing regioregular poly(3-hexyl thiophene) via anionic macroinitiation method and their self-assembly behavior. , 2007, Journal of the American Chemical Society.

[33]  R. D. Mccullough,et al.  High Field‐Effect Mobilities for Diblock Copolymers of Poly(3‐hexylthiophene) and Poly(methyl acrylate) , 2007 .

[34]  Yongye Liang,et al.  Conjugated block copolymers and co-oligomers: from supramolecular assembly to molecular electronics , 2007 .

[35]  R. Mezzenga,et al.  Weakly segregated smectic C lamellar clusters in blends of rods and rod-coil block copolymers , 2007 .

[36]  A. Jen,et al.  Theoretical and experimental studies on the surface structures of conjugated rod-coil block copolymer brushes. , 2007, Langmuir : the ACS journal of surfaces and colloids.

[37]  Yan Song,et al.  Nonvolatile polymer memory device based on bistable electrical switching in a thin film of poly(N-vinylcarbazole) with covalently bonded C60. , 2007, Langmuir : the ACS journal of surfaces and colloids.

[38]  Wen‐Chang Chen,et al.  Morphological Transformation and Photophysical Properties of Rod‐Coil Poly[2,7‐(9,9‐dihexylfluorene)]‐block‐poly(acrylic acid) in Solution , 2006 .

[39]  Shinuk Cho,et al.  Relationship between the microscopic morphology and the charge transport properties in poly(3-hexylthiophene) field-effect transistors , 2006 .

[40]  J. Ouyang,et al.  Electrical Switching and Bistability in Organic/Polymeric Thin Films and Memory Devices , 2006 .

[41]  D. Kwong,et al.  A dynamic random access memory based on a conjugated copolymer containing electron-donor and -acceptor moieties. , 2006, Angewandte Chemie.

[42]  M. Thompson,et al.  Living Radical Polymerization of Bipolar Transport Materials for Highly Efficient Light Emitting Diodes , 2006 .

[43]  Philip M. Rice,et al.  Organic Materials and Thin‐Film Structures for Cross‐Point Memory Cells Based on Trapping in Metallic Nanoparticles , 2005 .

[44]  Elena E. Sheina,et al.  Regioregular poly(3-alkylthiophene) conducting block copolymers , 2005 .

[45]  I. Hamley.  Block Copolymers in Solution: Fundamentals and Applications , 2005 .

[46]  I. Hamley.  Block Copolymers in Solution: Fundamentals and Applications: Hamley/Block Copolymers in Solution: Fundamentals and Applications , 2005 .

[47]  Yang Yang,et al.  Organic Donor–Acceptor System Exhibiting Electrical Bistability for Use in Memory Devices , 2005, Advanced materials.

[48]  Yan Song,et al.  Non‐Volatile Polymer Memory Device Based on a Novel Copolymer of N‐Vinylcarbazole and Eu‐Complexed Vinylbenzoate , 2005 .

[49]  Charles R. Szmanda,et al.  Programmable polymer thin film and non-volatile memory device , 2004, Nature materials.

[50]  J. Pflaum,et al.  Effect of Molecular Weight and Annealing of Poly(3‐hexylthiophene)s on the Performance of Organic Field‐Effect Transistors , 2004 .

[51]  G. Hadziioannou,et al.  Donor-acceptor diblock copolymers based on PPV and C-60: Synthesis, thermal properties, and morphology , 2004 .

[52]  D. Moses,et al.  Templating Organic Semiconductors via Self-Assembly of Polymer Colloids , 2003, Science.

[53]  G. Krausch,et al.  Nanostructured Thin Films via Self‐Assembly of Block Copolymers , 2002 .

[54]  Tomasz Kowalewski,et al.  Tuning the electrical conductivity and self-assembly of regioregular polythiophene by block copolymerization: nanowire morphologies in new di- and triblock copolymers. , 2002, Angewandte Chemie.

[55]  E. Samulski,et al.  Javelin-, Hockey Stick-, and Boomerang-Shaped Liquid Crystals. Structural Variations on p-Quinquephenyl† , 2001 .

[56]  G. Hadziioannou,et al.  Synthesis of a Conjugated Macromolecular Initiator for Nitroxide-Mediated Free Radical Polymerization. , 2001, Angewandte Chemie.

[57]  Gilles Horowitz,et al.  Theory of the organic field-effect transistor , 1999 .

[58]  Robert S. Loewe,et al.  A Simple Method to Prepare Head‐to‐Tail Coupled, Regioregular Poly(3‐alkylthiophenes) Using Grignard Metathesis , 1999 .

[59]  S. Jenekhe,et al.  Self-assembly of ordered microporous materials from rod-coil block copolymers , 1999, Science.

[60]  S. Jenekhe,et al.  Self-assembled aggregates of rod-coil block copolymers and their solubilization and encapsulation of fullerenes , 1998, Science.

[61]  J. Simmons,et al.  New conduction and reversible memory phenomena in thin insulating films , 1967, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.