Study of the charge transfer in organic devices for electrical charge injection

Abstract

This project, to be developed at Bangor University (UK) under the supervision of Prof. Dr. David Martin Taylor, is an extension of the project "Development of an organic device for electrical charge injection" (FAPESP Process 2011/21302-0) developed at the same university between March and August 2012. At that time it was not possible to continue the work due to issues related to immigration visa, and so the FAPESP Scientific Department decided in a very exceptional way to pre-approved this new BEPE for a period of six months in order to allow the continuity of the project. The results obtained during the first stage in Bangor allowed to conclude a systematic study on poly(amide-imide) (PAI) and get the first information about the interface formed between the insulators PAI/PSQ/SU8 and the semiconductor poly(3-hexylthiophene) (P3HT). Although other materials can be tested, the project reached sufficient maturity to allow the initialization of the manufacturing and the first studies with the organic charge injection devices (CIDs). The CID is an already known device in his inorganic version, being the principal objective of this project to perform a conclusive study on the possibility of preparing an organic version and explore its potential to act as a charge coupled device (CCD). A successful outcome will provide the opening for a new class of organic devices for image and signal processing. The CID is also an excellent test structure for fundamental studies on the effects of capture and release of carriers by traps existing at the insulator/semiconductor interface, providing essential information for the operation of organic field effect transistors (OFETs). To investigate the properties of the devices, measurements of capacitance as a function of voltage (C-V) and of the displacement currents will be undertaken. As a result, is expected to improve the efficiency of charge transfer along the insulator/semiconductor interface, providing the first definitive study on the feasibility of an organic CCD. The investigation of the combinations insulator/semiconductor for such applications will also stimulate the improvement of OFETs, in consonance with the main postdoctoral project developed in Brazil. (AU)