Importance of Simulation Studies in Analysis of Thin Film Transistors Based on Organic and Metal Oxide Semiconductors

Abstract

Organic semiconductors and metal oxides (such as ZnO) have recently been recognized as a new class of electronic materials for thin film transistor (TFT) applications such as active matrix displays, identification tags, sensors and other low end consumer applications (Campbell et al, 2007; Fortunato et al, 2008; Masuda et al, 2003; Nelson et al, 1998; Sandberg et al, 2002). Owing to their low cost, large area coverage, and at par or better performance, these materials are also considered to have enormous potential to replace amorphous silicon for use in existing and new electronic device applications. From the device technology and fabrication point of view, there have been rapid developments in this area over the past decade, but the field is still very much nascent in gaining the fundamental understanding, both, at the material and the device physics level. For example, whereas, vanderwal bonded organic semiconductors often suffers from spatial and energetic disorder (Pope et al, 1999), ZnO has very rich defect chemistry (Ozgur et al, 2005; McCluskey et al 2009). Additionally, they tend to have complex interaction with several surfaces, which often results in phenomenon difficult to explain by classical theories. It is therefore critical that the research in this area is necessarily be coupled with theoretical perspective in order to resolve several of the important issues, which will help in further enhancing its progress. In traditional electronics, device modelling and simulation has proven to be of great help in not only understanding the detailed device operation but has also served as a powerful tool to design and improve devices. The physics based device simulation is also becoming beneficial to the research area of organic and metal oxide semiconductors TFTs, where it is effectively predicting the device behaviour, giving insight into the underlying microscopic mechanisms and providing intuitive information about the performance of a new material (Bolognesi, 2002; Gupta et al, 2008, 2009, 2010; Hill, 2007; Hossain, 2003; Scheinert, 2004). Its continued involvement for explaining various device phenomenons will certainly be of great use for future developments.