Low-voltage organic light-emitting field-effect transistors using n-Dodecylphosphonic acid-passivated HfOx dielectrics

Abstract

In this paper, organic light-emitting field effect transistors (OLEFETs) operating at low voltages |V-op| below 10 V were first produced and characterized. n-Dodecylphosphonic acid (PA-C12)-self-assembled monolayer (SAM)-passivated HfOx dielectrics prepared using sol-gel chemistry decreased the device-operating voltages. Crystalline organic active layers of pentacene and N, N'-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (P13) acted as p-and n-type materials, respectively. 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran doped onto a tris(8-hydroxyquinoline) aluminum (Alq(3):DCM) layer was used as a light-emitting medium to enhance the luminescence efficiency. Based on a tri-layered structure with balanced ambipolar transports and the combined high capacitance-low leakage current of the PA-C12-SAM-treated HfOx dielectrics, the OLEFETs demonstrated good device performance with light emission at |V-op| < 10 V. The transistor characteristics and operating light-emission mechanisms were discussed based on the EL images acquired using a charge-coupled device (CCD) camera under ambient conditions. (C) 2017 Elsevier B.V. All rights reserved.