p‐Doping Poly(3‐hexylthiophene) in Solvent Mixtures

Abstract

One method to improve the conductivity of conjugated polymers, like poly(3‐hexylthiophene) (P3HT), is to “chemically dope” them analogous to inorganic materials. One electron acceptor that has been used in tandem to p‐doped P3HT is 2,3,5,6‐tetrafluoro‐7,7,8,8‐tetracyanoquinodimethane (F4TCNQ), and recently there has been much interest in the nature of the interactions between F4TCNQ and P3HT in the solution phase. To date, however, there are few reports that investigate the behavior of F4TCNQ‐doped P3HT in binary solvent mixtures. The study reported herein is an investigation of F4TCNQ‐doped P3HT in mixtures of chloroform (CF) with dichloromethane (DCM) or acetonitrile (AcN), wherein variations in the doping efficiency in these mixtures are observed using UV–vis absorption, Raman, and electron paramagnetic resonance spectroscopic techniques. The contrasting solubility and charge transfer behavior of F4TCNQ‐doped P3HT in CF:DCM and CF:AcN show that judicious selection of solvent mixtures may be exploited to improve the doping efficiency and solution processability of p‐doped P3HT dispersions.

The importance of a good solvent of conjugated polymers for preparing dopant solution on the electrical and mechanical properties of sequentially doped conjugated polymer films

“…For codeposition, the polymer and the dopant are mixed together in a cosolvent at the desired mixing ratio; however, the doping process leads to high aggregation, forming undesired structures in the solution and resulting in poor quality when cast into films. 4,5 In sequential processing, the polymer film is cast first and then the dopant is infiltrated in a second solution or in a gas-phase step. It is a versatile technique to produce high-quality doped semiconducting polymer films.…”

Influence of Various Doping Agents on Organic Semiconductors’ Physicochemical Properties

“…13,14 The electron-reach π-conjugated system of organic semiconductors chemical p-type doping is easily achievable contrary to the ntype doping where strong reducing agents are required. Compounds that can be applied as p-doping agents are: molecular halogens, 15 FeCl 3 , 12,16 AsF 5 , 17 AlCl 4 − , 3 PF 6 − , 18 TFSI, 19 dodecaborane, 20 heteropolyanions, [21][22][23] transition-metal salts, 24 fullerenes, 25,26 tellurium quantum dots, 27 microcrystalline CdS, 28 TiO 2 nanoparticles, 29 oxygen, [30][31][32][33] ozone, 34 magnetic transition-metal complexes, 35 organic anions, [36][37][38] including surfactants, 39 organic molecules including F4-TCNQ [40][41][42] via partial charge transfer and molecular complex formation, [43][44][45][46] chiral compounds, 47 drugs like naproxen, 48 ionic liquids like [EMIM][TCM]. 49 Inorganic dopants result in better conductivity than organic dopants and large dopants like polymers, e.g., PEDOT:PSS, PEDOT:polyarylethersulfone, 7 PANI: Polyacrylic acid, 50 where doping is an acid-base reaction.…”