Preparation and characterization of an organic field effect transistor using a vertical architecture

Abstract

Organic transistors have emerged in the 1980s with the purpose to allow the study of the properties of the materials involved. The increase on the carrier mobility in organic semiconductors has enabled the fabrication of organic transistors with reasonable performance, allowing some practical applications of these devices. However, due to the low density of charge, the performance of organic transistors is still poor, requiring further development of new optimized structures. A promising possibility is to prepare transistors in a vertical architecture, where the source and drain electrodes are horizontally arranged and, therefore, the conduction occurs in the vertical direction, the channel width being determined by the thickness of the semiconductor layer itself. This master's project proposes the preparation of a Vertical Organic Field Effect Transistor (VOFET) using gold (Au) or aluminium (Al) electrodes, poly(3-hexylthiophene) (P3HT) as the semiconducting material and polysilsesquioxane (PSQ) or aluminium oxide (Al2O3) as the insulating materials. P3HT and PSQ will be deposited by spin-coating, while the Al2O3 is obtained by anodization. The electrical characterization of VOFETs will be performed by obtaining the transfer and output curves, through which parameters such as mobility, on/off ratios and threshold voltage (VT) can be obtained, allowing the evaluation of the devices performance. The project aims to contribute for the improvement of organic transistors by using different architectures of manufacturing. Successful investigations will allow the development of devices for application in flexible organic circuits. (AU)