Improvements in Stability and Performance of N,N’-dialkyl Perylene Diimide-Based n-Type Thin-Film Transistors
A stable and high performance n-type field-effect transistor made of PDI-C8 or PDI-C13 by optimized growth rate and sulfur-modified Au electrode.
Low-temperature processable organic semiconductors offer intriguing prospects for inexpensive, flexible, large-area applications, such as displays, radio-frequency identification tags, circuits, and sensors. For organic thin-film transistor (OTFT) applications, n-type organic semiconductors with performance comparable to p-type materials, such as pentacene, are of great importance in order to realize the benefits of complementary circuit design. Perylene and naphthalene diimides and their derivatives are well-known n-type organic semiconductors because of their robust nature, flexible molecular orbital energetics, and excellent charge transport properties that could be tailorable via judicious functionalization. However, although perylene diimides exhibit outstanding mobilities greater than 0.6 cm2·V–1·s–1, the OTFTs can only work in vacuum or under an inert atmosphere.Here we increased the stability and performance for N,N’-dioctyl perylene diimide (PDI-C8) and N,N’-ditridecyl perylene diimide (PDI-C13) thin-film transistors by optimized growth rate and sulfur-modified electrode. We have also demonstrated that the grain size and the depth of grain boundaries greatly influence the stability for these TFTs, and this knowledge can be applied to the explanation of the air stability for other perylene diimides without electron-withdrawing groups.
Advanced Materials , 2009, 21(16), 1631-1635