Low Voltage Operable Eco-Friendly Water-Induced LiOxDielectric Based Organic Field Effect Transistor

Abstract

In this letter, we report water-induced Lithium oxide (LiO x) based Organic field effect transistors with operating voltage under -2 V which combine the advantages of the floating film transfer method by using water as a liquid substrate for a self-assembled poly [2,5-(2-octyldodecyl)-3,6-diketopyrrolopyrrole-alt-5,5-(2,5di (thien-2-yl)thieno [3,2-b]-thiophene)] (DPP-DTT) semicond- ucting layer. The devices demonstrated maximum saturation mobility ( μ max) of 0.184 cm 2 V-1 sec -1 , average mobility ( μ avg) of 0.14 (±0.035) cm 2 V-1 sec -1 , Iscriptscriptstyle ON/I scriptscriptstyle OFF ratio of ∼ 104 ,and threshold voltage ( VTH) of ∼ 1.12 (±0.3) V. The devices exhibited a subthreshold swing of 186 (±15) mV/decade and a surface trap density (Nss of 4.63 (±0.42) × 1012 cm-2.eV -1. Deionized water is used for making the precursor solution of lithium oxide from lithium nitrate without using any toxic additive, making it low cost and eco-friendly synthesis. LiOx based dielectric processed at 300 °C showed leakage current density of 1.6 × 10-8 A/cm2 at 1 MV/cm and capacitance of 380 (±18) nF/cm2. © 1980-2012 IEEE.