Conduction processes in conjugated, highly regio-regular, high molecular mass, poly(3-hexylthiophene) thin-film transistors

Abstract

Highly regio-regular poly(3-hexylthiophenes) (P3HT) thin films have been produced using the Tzrnadel method. They have head to tail counts approaching very close to 100% and high molecular mass. Thin-film transistors and Schottky diodes have been used to study the effects of counter ion and carrier density on field-effect and bulk mobility, respectively. The density of counter ions was increased using 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and had a profound effect on both the field effect and bulk mobility with a ratio between the two of 102, in a similar way to DDQ in poly(β′-dodecyloxy-α,α′,-α′,α″terthienyl) (polyDOT3), but with substantially higher drift mobilities. A method is described, using Schottky barriers, of simply and accurately determining carrier drift mobility. The effect of carrier density on hole mobility is believed to be indirect, filling traps in the regions separating the highly ordered domains until trap free conduction and hence high mobility is reached.

High‐Performance Photoresponsive Organic Nanotransistors with Single‐Layer Graphenes as Two‐Dimensional Electrodes

“…4B, calculated using the standard method). Both of these values are comparable to those obtained from bulk organic FETs based on metal electrodes, [52][53][54][55] strongly suggesting that cut 2D planar graphene sheets can function as efficient electrodes, realizing the functions of macroscopic metal electrodes at the nanometer scale. We found that the threshold voltage (V T ) in these devices is approximately þ95 V, a significant positive shift.…”

Tuning the Dimensions of C60-Based Needlelike Crystals in Blended Thin Films

“…Polyalkylthiophenes have been found to be an interesting class of conductive polymers because of their good solubility, high chemical stability, and high charge-carrier mobility. [25][26][27] Padinger et al first reported that thermal annealing of the P3HT:PCBM blend resulted in an improvement in solarcell properties. [8] Yang et al found that thermal annealing induces an enhanced crystallization of P3HT, explaining the improvement in solar-cell performance.…”

Dependence of Regioregular Poly(3-hexylthiophene) Film Morphology and Field-Effect Mobility on Molecular Weight

“…High-mobility polymer TFTs (mobility of 0.01-0.1 cm 2 /(V s)) have been made with poly(9,9′-dioctylfluorene-co-bithiophene) (F8T2), 9,10 poly[5,5′-bis(3-dodecyl-2-thienyl)-2,2′-bithiophene] (PQT), 11,12 and regioregular poly(3-hexylthiophene) (P3HT). [13][14][15][16][17] The charge carrier mobility of P3HT has been related to the regioregularity, 18 numberaverage molecular weight (MW), 19,20 casting solvent, 13,21 and carrier concentration. 22 The properties of polyfluorene films also depend on MW.…”