Non‐Peripheral Tetrahexyl‐Substituted Vanadyl Phthalocyanines with Intermolecular Cofacial π–π Stacking for Solution‐Processed Organic Field‐Effect Transistors

Abstract

Four structural isomers of non‐peripheral tetrahexyl‐substituted vanadyl phthalocy­anine can be easily separated using common laboratory column chromatography on a gram scale. The most abundant isomer, 1,8,18,22‐tetrahexyl vanadyl phthalocyanine (I‐3), adopts intermolecular 2D cofacial π–π stacking and exhibits a field‐effect mobility of up to 0.13 cm2 V−1 s−1.

Dopant‐Free Hole‐Transporting Layer Based on Isomer‐Pure Tetra‐Butyl‐Substituted Zinc(II) Phthalocyanine for Planar Perovskite Solar Cells

“…The obtained hole mobility of RE ‐ZnBu 4 Pc and ZnBu 4 Pc are 7.59 × 10 −4 and 4.78 × 10 −4 cm 2 V −1 s −1 , respectively, which are higher than that of spiro‐OMeTAD (8.09 × 10 −5 cm 2 V −1 s −1 ) . According to the results, higher mobility was achieved for the isomer‐pure HTM, which is in line with the reported values for different isomers of tetrahexyl‐substituted vanadyl phthalocyanines, published by Dong et al In their study, the highest hole mobility has been obtained for the isomer I‐3 , in which the arrangement of four hexyl substituents in nonperipheral positions of Pc ring is completely similar to the arrangement of n ‐butyl groups in peripheral positions of RE ‐ZnBu 4 Pc. The higher hole mobility obtained for RE ‐ZnBu 4 Pc can also be explained by the higher crystallinity of this compound in thin‐film state, originated from its isomer purity (as stated below).…”

“…In a study, field‐effect transistor (FET) mobility of four purified isomers of nonperipheral tetrahexyl‐substituted vanadyl phthalocyanine is identified. Different mobilities, varying from 10 −4 to 10 −1 cm 2 V −1 s −1 , are measured for various isomers of the Pc compound, and the highest value of 0.13 cm 2 V −1 s −1 is obtained for the most abundant isomer, 1,8,18,22‐tetrahexyl vanadyl phthalocyanine . All these studies strongly confirm the importance of using isomer‐pure HTMs in PSCs.…”

ABAB‐Symmetric Tetraalkyl Titanyl Phthalocyanines for Solution Processed Organic Field‐Effect Transistors with Mobility Approaching 1 cm2 V−1 s−1

“…On the other hand, discotic conjugated molecules are believed to be promising solution processible OSCs since they have two‐dimensional (2D) conjugated cores and the molecules can self‐assemble into column nanostructures in which adjacent molecules experience a much large π‐orbital overlap for efficient charge transport 9. A number of solution processsible discotic OSCs have been synthesized for OFETs 10–19. However, so far only a few of them exhibit field‐effect mobility in the level of 10 −1 cm 2 V −1 s −1 12, 13…”

“…A number of solution processsible discotic OSCs have been synthesized for OFETs 10–19. However, so far only a few of them exhibit field‐effect mobility in the level of 10 −1 cm 2 V −1 s −1 12, 13…”

“…All these features imply that MPcs can be high mobility solution processible OSCs by introducing carefully selected solubilizing groups in the appropriate positions of Pc ring. In fact, various solution processible Pcs have been synthesized for OFET fabrication by placing substituents on the Pc ring at the peripheral or non‐peripheral benzo‐sites 12–19. But all these Pcs have substituents distributed in all four outer phenyl rings.…”