Organic Thin Film Transistors Based on 2,3‐Dimethylpentacene and 2,3‐Dimethyltetracene

Abstract

Abstract2,3‐Dimethylpentacene (DMP) and 2,3‐dimethyltetracene (DMT) were synthesized, characterized and employed as the channel material in the fabrication of thin‐film transistors. The two methyl groups increase the chemical stability of the compounds versus the pristine acene analogues. The crystals maintain herringbone‐like molecular packing, whereas the weak dipole associated with the unsymmetrical molecule induces an anti‐parallel alignment among the neighbors. This structural motif favors layered film growth on SiO2/Si surface. Thin film transistors prepared on SiO2/Si and n‐nonyltrichlorosilane‐modified SiO2/Si at different substrate temperatures were compared. DMP‐based transistors prepared on rubbed n‐nonyltrichlorosilane‐modified SiO2/Si substrate gave the highest field‐effect mobility of 0.46 cm2/Vs, whereas DMT‐based transistor gave a mobility of 0.028 cm2/Vs.