Product Code M681
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7,7,8,8-tetracyanoquinodimethane (TCNQ), with a LUMO at 4.5 eV, is known for the charge-transfer salts formed by its radical anion TCNQ in photovoltaic, light-emitting diodes, and organic field-effect transistor devices. TCNQ and its derivatives have been used as dopants, leading to an increase in hole mobility or to the lowering of injection barriers. One classic example of such is the treatment of tetrathiafulvene (TTF), an electron donor with TCNQ. TFF and TCNQ form an ion pair, the TTF-TCNQ complex. This process of doping leads to the crystallisation of the ion pair into a one-dimensionally stacked polymer. This polymer consists of segregated stacks of cations and anions of the donors and the acceptors, respectively. The complex crystal is an organic semiconductor that exhibits metallic electric conductivity [1, 2].

It also has been shown that TCNQ can effectively modify Cu or Ag surfaces. The formation of Cu-TCNQ and Ag-TCNQ enhances the work function of such electrodes and reduces the hole injection barrier dramatically. Furthermore, it improves electrode/organic layer contact, hence the reduction of contact resistances [3].

Tetracyanoquinodimethane (TCNQ) is also found to act as a p-type doping agent of graphene films due to its powerful electron-accepting capacity [4].

General Information

CAS number 1518-16-7
Chemical formula C12H4N4
Molecular weight 204.19 g/mol
HOMO/LUMO LUMO = 4.5 eV
Synonyms
  • 7,7,8,8-Tetracyanoquinodimethane
  • (2,5-Cyclohexadiene-1,4-diylidene)-dimalononitrile
  • 2,2'-(2,5-Cyclohexadiene-1,4-diylidene)bismalononitrile
Classification / Family

Electron acceptor, Hole-injection materials, Hole transport layer material, Light-emitting diodes, Polymer solar cells, OFETs.

Product Details

Purity

 >99.0% (sublimed)

 >98.0% (unsublimed)
Melting point 289 °C (dec.)
Appearance Dark yellow to brown crystals/powder

*Sublimation is a technique used to obtain ultra pure-grade chemicals. For more details about sublimation, please refer to the Sublimed Materials for OLED devices page.

Chemical Structure

Chemical structure of TCNQ
Chemical structure of 7,7,8,8-tetracyanoquinodimethane (TCNQ)

Device Structure(s)

Device structure ITO/0.4 wt% F4TCNQ doped α NPD (30 nm)/ 5 wt% Ir (ppy)3 doped CBP (50 nm)/BPhen (30 nm)/20 wt% TCNQ mixed BPhen (1.5 nm)/Al [5]
Colour Green   green
Luminance@15 V 1,320 cd/m2 
Power Efficiency@14 V 56.6 lm W1  
Current Efficiency@14 V 23.17 cd/A
Device structure ITO/F4TCNQ (3 nm)/MeO-Spiro-TPD (27 nm)/CBP + BCzVbi* (50 nm)/BPhen (10 nm)/TCNQ mixed BPhen (1.5 nm)/Al [6]
Colour Red   red
Luminance@ 10 mA/cm2 1,790 cd/m2
Power Efficiency@ 10 mA/cm2      4.65 lm W1  
Current Efficiency@ 10 mA/cm2 18.0 cd/A

*For chemical structure information, please refer to the cited references.

Characterisation

hplc trace of tcnq
HPLC trace of 7,7,8,8-tetracyanoquinodimethane (TCNQ)

Pricing

 Grade Order Code Quantity Price
Sublimed (>99.0% purity) M681 1 g £127.00
Unsublimed (>98.0% purity) M682 5 g £88.00
Sublimed (>99.0% purity) M681 5 g £509.00

MSDS Documentation


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.