The Quinonoid Zwitterion Interlayer for the Improvement of Charge Carrier Mobility in Organic Field-Effect Transistors

• Published in: Polymers Vol. 13; no. 10; p. 1567
• Main Authors: Luczak, Adam, Ruiz, Angélina Torres, Pascal, Simon, Adamski, Adrian, Jung, Jarosław, Luszczynska, Beata, Siri, Olivier
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 13.05.2021; MDPI
• Subjects: Carrier mobility; charge carrier trapping; Chemical Sciences; Contact angle; Current carriers; Dielectrics; Electric fields; Electronics; electrostatic force microscopy; Engineering Sciences; Field effect transistors; interface; Interfaces; Interlayers; Metal oxides; Organic chemistry; organic field-effect transistors; Screen printing; Semiconductor devices; Semiconductors; Silicon wafers; Solvents; Transistors; zwitterionic benzoquinonemonoimine; Zwitterions; Germany; zwitterionic benzoquinonemonoimine; electrostatic force microscopy; interface; organic field-effect transistors; charge carrier trapping
• ISSN: 2073-4360; 2073-4360
• DOI: 10.3390/polym13101567

The interface between the semiconductor and the dielectric layer plays a crucial role in organic field-effect transistors (OFETs) because it is at the interface that charge carriers are accumulated and transported. In this study, four zwitterionic benzoquinonemonoimine dyes featuring alkyl and aryl N-substituents were used to cover the dielectric layers in OFET structures. The best interlayer material, containing aliphatic side groups, increased charge carrier mobility in the measured systems. This improvement can be explained by the reduction in the number of the charge carrier trapping sites at the dielectric active layer interface from 1014 eV−1 cm−2 to 2 × 1013 eV−1 cm−2. The density of the traps was one order of magnitude lower compared to the unmodified transistors. This resulted in an increase in charge carrier mobility in the tested poly [2,5-(2-octyldodecyl)-3,6-diketopyrrolopyrrole-alt-5,5-(2,5-di(thien-2-yl)thieno [3,2-b]thiophene)] (DPPDTT)-based transistors to 5.4 × 10−1 cm2 V−1 s−1.