Printed field effect transistors

Abstract

This final year project will explore the feasibility of fabricating inkjet printed devices, specifically Organic Field Effect Transistors (OFETs). This study will report important processing conditions, design fabrications, methodology and materials selection, which have profound effect on the electrical performance of printed devices. This project focuses on the use of inkjet print technology to fabricate low cost organic devices.

The conductivity of electrodes is carried out to investigate if conductivity plays a major role in affecting the electrical performance of OFETs. The surface morphology of the electrodes and gate insulator are explored because uniformity is crucial to the device’s performance.

The two various investigations and comparisons made are: 1) Inkjet printed organic semiconductor poly(3,3’’’-dialkyl-quaterthiophene) (PQT) with respect with thermal evaporated small molecule pentacene. 2) Different inkjet printed source drain electrodes namely, poly(3,4- ethylenedioxythiophene/poly(styrene sulfonate) (PEDOT/PSS) and silver nanoparticles (AgNP).

Transfer characteristics and output characteristics graph are used to explain the electrical performance of the respective fabricated OFETs.

To wrap up on the report, a concise conclusion is discussion. Two recommendations are made to produce devices with higher electrical performance.