2:45 PM - 3:15 PM
▲ [19p-W521-3] High-performance organic transistors and printed LSIs
Keywords:organic semiconductor,organic transistor
This presentation focuses on recent development of key technologies for printed LSIs which can provide future low-cost platforms for RFID tags, AD converters, data processors, and sensing circuitries. Such prospect bears increasing reality because of recent research innovations in the field of material chemistry, charge transport physics, and solution processes of printable organic semiconductors. Achieving band transport in state-of-the-art printable organic semiconductors, carrier mobility is elevated above 15 cm2/Vs, so that reasonable speed in moderately integrated logic circuits can be available. With excellent chemical and thermal stability for such compounds, we are developing simple integrated devices based on CMOS using p-type and n-type printed organic FETs. Particularly important are new processing technologies for continuous growth of inch-size organic single-crystalline semiconductor “wafers” from solution and for lithographical patterning of semiconductors and metal electrodes. Successful rectification and identification are demonstrated at 13.56 MHz with printed organic CMOS circuits for the first time.
Development of functional materials and understanding of the microscopic mechanisms mutually benefit through their close interaction. To accelerate development of organic semiconductor devices for industrial application to flexible and printed electronics, it is essential to understand mechanisms of charge transport in conjunction with molecular-scale charge transfer. Here, we examine the idea that high-mobility charge transport in newly developed solution-crystalized organic transistors is caused by band-like charge transport, using several different molecular systems as the active semiconductor layers. These materials, which potentially realize the highest-speed organic transistors, can be categorized as “high-end” organic semiconductors characterized by coherent electronic states and high values of mobility close to or even exceeding 10 cm2/Vs, being essentially different from conventional lower-mobility organic semiconductors with basically incoherent hopping-like transport as studied in the previous century. We employ Hall-effect measurement which differentiates the coherent band transport from site-to-site hopping.
Various materials are crystalized to fabricate high-mobility organic field-effect transistors (OFETs) and their charge transport is investigated through temperature dependent four-terminal conductivity, Hall-effect and pressure-dependent measurements. The measured materials range from conventional polyacenes such as pentacene and rubrene, recently developed high-mobility heteroacenes. Furthermore, we developed solution processes for inch-size single-crystalline films of high-mobility organic semiconductor to provide a platform for high-speed integrated devices. We present a method of continuously growing large-domain organic semiconductor crystals to fabricate multi-array high-mobility organic transistors.
Development of functional materials and understanding of the microscopic mechanisms mutually benefit through their close interaction. To accelerate development of organic semiconductor devices for industrial application to flexible and printed electronics, it is essential to understand mechanisms of charge transport in conjunction with molecular-scale charge transfer. Here, we examine the idea that high-mobility charge transport in newly developed solution-crystalized organic transistors is caused by band-like charge transport, using several different molecular systems as the active semiconductor layers. These materials, which potentially realize the highest-speed organic transistors, can be categorized as “high-end” organic semiconductors characterized by coherent electronic states and high values of mobility close to or even exceeding 10 cm2/Vs, being essentially different from conventional lower-mobility organic semiconductors with basically incoherent hopping-like transport as studied in the previous century. We employ Hall-effect measurement which differentiates the coherent band transport from site-to-site hopping.
Various materials are crystalized to fabricate high-mobility organic field-effect transistors (OFETs) and their charge transport is investigated through temperature dependent four-terminal conductivity, Hall-effect and pressure-dependent measurements. The measured materials range from conventional polyacenes such as pentacene and rubrene, recently developed high-mobility heteroacenes. Furthermore, we developed solution processes for inch-size single-crystalline films of high-mobility organic semiconductor to provide a platform for high-speed integrated devices. We present a method of continuously growing large-domain organic semiconductor crystals to fabricate multi-array high-mobility organic transistors.