PBTTT

Order Code: M141
MSDS sheet

Price

(excluding Taxes)

£499.00

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Poly(2,5-bis(3-hexadecylthiophen-2-yl)thieno[3,2-b]thiophene) known as PBTTT and PBTTT-C16.

No longer stocked - please see DPP-DTT as a higher mobility, higher stability alternative.

PBTTT has an increased mobility, stability, backbone rigidity and crystallinity compared to P3HT [1] and has demonstrated hole mobilities as high as 1 cm2/Vs [2]. Combined with good solubility in a range of common solvents this makes it possible to achieve high performance using a number of different coating techniques with mobilities as high as 0.1 cm2/Vs having been achieved with inkjet printing [3]. However, the advantages of PBTTT are not just better mobility and stability but also the opportunity for new and interesting science related to:

  • Liquid crystal behaviour [1]
  • Large crystal domains with easily identifiable boundaries [4]
  • Molecular terracing [5]
  • Anisotropic behaviour in the ribbon phase [6]
  • Luttinger liquid behaviour [7]

References (please note that Ossila has no formal connection to any of the authors or institutions in these references):

    1. Liquid-crystalline semiconducting polymers with high charge-carrier mobility, I. McCulloch et al., Nature materials, 5, 328 (2006)
    2. Undoped Polythiophene field-effect transistors with a mobility of 1 cm2 V-1 S-1, B.H. Hamadani et al., Applied Physics letters, 91, 243512 (2007)
    3. Ink-jet printed p-type polymer electronics based on liquid-crystalline polymer semiconductors, M. Baklar et al., Journal of Materials Chemistry, 20, 1927 (2010)
    4. In-Plane Liquid Crystalline Texture of High-Performance Thienothiophene Copolymer Thin Films, X. Zhang et al. Advanced Functional Materials, 20, 4098 (2010)
    5. Anisotropy of Charge Transport in a Uniaxially Aligned and Chain-Extended, High-Mobility, Conjugated Polymer Semiconductor, M.J. Lee et al., Advanced Functional Materials, 21, 932 (2011)
    6. Controlling the Orientation of Terraced Nanoscale "Ribbons" of a Poly(thiophene) Semiconductor, D.M. DeLongchamp et al., ACS Nano, 3, 780 (2009)
    7. Nonlinear transport in semiconducting polymers at high carrier densities, J.D. Yuen et al., Nature Materials, 8, 572 (2009)

     

    Datasheet

    PBTTT chemical structure (Thienothiophene thiophene Copolymer)
    Chemical structure of PBTTT-C16.

    Specifications

    Full name Poly(2,5-bis(3-hexadecyllthiophen-2-yl)thieno[3,2-b]thiophene)
    Chemical formula (C46H70S4)n
    MW 39,500 g/mol
    PDI 1.95

     

    Solubility of PBTTT

    The recommend solvent is 1,2-Dichlorobenzene (10 mg/mL @ 80°C). You can use alternative solvents such as Tetralin, Decalin or Indan but it should be noted that these solvents will require heating to 80°C. Gelation can occur on cooling the solution. This is a reversible process and the solution can be restored on heating or prevented for a hours-days if kept warm (50-60°C).

    Absorption (max, thin film) 550 nm
    DSC (2nd heat cycle/peak) T1 110°C T2 220°C
    Solvents Chloroform, Chlorobenzene, Dichlorobenzene, THF

     

    Electrical properties of PBTTT

    Field effect mobility (Max) 1.0 x 10-1 cm2/Vs
    On/Off Ratio (Max) 107
    Vo 20 V (with SiO2 dielectric)
    HOMO / LUMO HOMO = -5.1 eV LUMO = -3.1 eV

    This data represents typical values obtained from Mercks own device configuration. The ionisation energy was measured using a Riken-AC2 spectrophotometer.

     

    Storage and stability of PBTTT

    Solid Polymer

    Storage Store in the dark under an inert atmosphere
    Temperature Can be heated to 180°C without degradation

    Processed Film Stability of PBTTT

    Storage Store in the dark under an inert atmosphere
    Thermal stability Stable up to 190°C under an inert atmosphere
    Atmospheric stability For the best results measurements and processing should be carried out under an inert atmosphere

     

    Note: Deposition of PBTTT from a warm solution gives highly uniform films.

    Processing example Bottom Gate Field Effect Transistor

    Bottom Gate Structure Material Process
    Substrate n-doped silicon/silicon dioxide (230 nm) as gate dielectric with Au electrodes (using ITO adhesion layer)

    Substrate cleaning:

      • Sonicated in water
      • Sonicated in acetone
      • Sonicated in IPA
      • Ozone treated
      Surface treatment layer OTS
      • Treatment is necessary to enhance transistor properties
      • OTS - 10 mM in toulene with 150 ppm water
      • Immerse substrate in the OTS solution for 20 min at 60°C
      OSC PBTTT
      • 10 mg/ml solution in 1,2-dichlorobenzene used
      • Spin at 3000 rpm, with 1s acceleration, for 3 min
      • Anneal at 100°C for 10 min
      • Processing under inert atmosphere is advised

       

      Typical values: μ = 1.0 x 10-1 cm2/Vs; On/Off = 107

       

      Processing example Top Gate Field Effect Transistor

       

      Top Gate Structure Material Process
      Substrate PEN
      • To clean: sonicate in methanol for 1 min then dry
      Source/Drain Au
      • Deposit to 30 nm thickness
      Contacts SAM M001
      • Cover substrate for 1 min before spinning
      • Spin at 500 rpm for 18 sec
      • Rinse with IPA
      OSC PBTTT
      • 5 mg/mL solution in 1,2-dichlorobenzene
      • Spin at 3000 rpm for 2 min
      • Anneal at 100°C for 1 min with cover
      • Processing in yellow light is advised
      Dielectric D139-FC43-045
      • Spin at 500 rpm for 10s with 3s acceleration
      • Final spin speed at 1000rp for 20s with 3s acceleration
      • Baked in oven at 100°C for 20 min
      • Approx. thickness of 500 nm
      Gate Au
      • Deposit to 30 nm thickness

       

      Typical Values: μ = 4.0 x 10-2 cm2/Vs; On/Off = 104

       

      To the best of our knowledge the technical information provided here is accurate. However, Ossila assume no liability for the accuracy of this information. The values provided here are typical at the time of manufacture and may vary over time and from batch to batch.