Organic transistors-based backplane for flat panel displays

Abstract

This project explores the design, performance enhancement, and integration of organic thin film transistors (OTFTs) into active matrix display backplane applications. Surface treatments using self-assembled monolayers (SAMs) to enhance OTFT mobility and carrier injection are explored. The use of inorganic silicon nitride and organic poly-4-vinylphenol (PVP) solution-processible dielectric material as the gate dielectric of the OTFT is investigated. Electrical parameters such as mobility, threshold voltage, subthreshold slope and interfacial trap densities are probed to investigate the impact of different dielectrics and surface treatments on OTFT performance.

Most OTFT research is restricted to discrete individual devices. This work aims to fabricate an array of OTFTs over an area typical of a small hand held display (e.g. mobile phone screen, 50 mm x 40 mm) so as to study the uniformity of organic and inorganic dielectrics and to prove the feasibility of organic electronics in modern-day electronic applications, especially in flat panel displays (FPDs). This is realized through circuit design, materials selection, fabrication and characterization of 8192 OTFTs in a 64 x 64 pixel matrix array. An organic-solution processible encapsulation layer is identified and implemented in order for high level integration of OLED onto the existing circuitry architecture. The matrix will be integrated with a third-party OLED process to demonstrate the functionality of the backplane matrix.