The Stoichiometry of TCNQ-Based Organic Charge-Transfer Cocrystals

Abstract

Organic charge-transfer cocrystals (CTCs) have attracted significant research attention due to their wide range of potential applications in organic optoelectronic devices, organic magnetic devices, organic energy devices, pharmaceutical industry, etc. The physical properties of organic charge transfer cocrystals can be tuned not only by changing the donor and acceptor molecules, but also by varying the stoichiometry between the donor and the acceptor. However, the importance of the stoichiometry on tuning the properties of CTCs has still been underestimated. In this review, single-crystal growth methods of organic CTCs with different stoichiometries are first introduced, and their physical properties, including the degree of charge transfer, electrical conductivity, and field-effect mobility, are then discussed. Finally, a perspective of this research direction is provided to give the readers a general understanding of the concept.

Greater than 10 cm2 V−1 s−1: A breakthrough of organic semiconductors for field‐effect transistors

“…16 Furthermore, some theoretical calculation results predict that even higher mobilities of greater than 100 cm 2 V −1 s −1 can be achieved in organic charge transfer cocrystals, 23 which drives us to find novel highperformance organic semiconductors for organic electronics. 24,25 It is important to summarize all of these novel molecules with mobilities of higher than 10 cm 2 V −1 s −1 since it can not only provide both chemists and physicists with a clear understanding of research history for organic semiconductors but also attract more attention for the commercial applications. In this review, organic semiconductors with mobility of greater than 10 cm 2 V −1 s −1 , including polymers and small molecules, are summarized.…”

Influence of Internal Molecular Motions in the Photothermal Conversion Effect of Charge-Transfer Cocrystals

“…The commercially available coformers TCNQ and TFBQ were selected as acceptor moieties due to the known capabilities of these fragments to establish CT interactions through the stabilization of radical anions formed . Single crystals of CP-TCNQ and CP - TFBQ were obtained via slow evaporation of saturated solutions of acetone and hexane/ethyl acetate, respectively.…”

Growth direction dependent separate-channel charge transport in the organic weak charge-transfer co-crystal of anthracene–DTTCNQ

“…60 For example, 7,7,8,8-tetracyanoquinodimethane (TCNQ) is a widely studied organic acceptor; when perylene is selected as the donor, the perylene-TCNQ co-crystal system experiences phase transition (roomtemperature phase 42,60 vs. low-temperature phase 61 ) and different stoichiometries (1 : 1, 2 : 1, and 3 : 1). 42,62 Furthermore, TCNQbased co-crystals can be insulators, 63 semiconductors, 42 or conductors, 64 depending on the donor. It is necessary to carefully consider the conditions (such as p-conjugation, 65 the degree of charge transfer, 26,[66][67][68] hydrogen bonding, 69 halogen bonding, 9,11,[70][71][72][73] and interface [74][75][76] ) so that we can get the desired molecules and properties via the molecular design.…”