Micrometer‐ and Nanometer‐Sized Organic Single‐Crystalline Transistors

The use of micrometer and nanometer‐sized organic single crystals to fabricate devices can retain all the advantages of single crystals, avoid the difficulties of growing large crystals, and provide a way to characterize organic semiconductors more efficiently. Moreover, the effective use of such “small” crystals will be beneficial to nanoelectronics. Here we review the recent progress of organic single‐crystalline transistors based on micro‐/nanometer‐sized structures, namely fabrication methods and related technical issues, device properties, and current challenges.     

Device Physics of Solution‐Processed Organic Field‐Effect Transistors

Field‐effect transistors based on solution‐processible organic semiconductors have experienced impressive improvements in both performance and reliability in recent years, and printing‐based manufacturing processes for integrated transistor circuits are being developed to realize low‐cost, large‐area electronic products on flexible substrates. This article reviews the materials, charge‐transport, and device physics of solution‐processed organic field‐effect transistors, focusing in particular on the physics of the active semiconductor/dielectric interface. Issues such as the relationship between microstructure and charge transport, the critical role of the gate dielectric, the influence of polaronic relaxation and disorder effects on charge transport, charge‐injection mechanisms, and the current understanding of mechanisms for charge trapping are reviewed. Many interesting questions on how the molecular and electronic structures and the presence of defects at organic/organic heterointerfaces influence the device performance and stability remain to be explored.     

Cover Picture: High‐Performance Organic Single‐Crystal Transistors on Flexible Substrates (Adv. Mater. 17/2006)

The cover shows a comparison of thin and thick rubrene single crystals where the flexibility of the thin rubrene crystals is clearly illustrated. On p. 2320, Yang, Bao, and co‐workers report that high performance flexible transistors on plastic substrates fabricated by using these rubrene “thin‐film” single‐crystals demonstrate mobility as high as 4.6 cm² Vs^–1 and ON/OFF ratios of approximately 10⁶.