Vertical organic triodes with a high current gain operated in saturation region

Abstract

High-current, low-cost field emission triode using a reticulated vitreous carbon cathode J. Vac. Sci. Technol. B 28, C2C37 (2010); 10.1116/1.3305455 Influence of thin metal base thickness on the performance of CuPc vertical organic triodes Appl. Phys. Lett. 90, 153509 (2007);

High-current operation of vertical-type organic transistor with preferentially oriented molecular film

“…The observed J DS was extremely high compared with those of other vertical-type organic transistors. [16][17][18][19][20][21][22][23][24][25][26] The gate current density (J G ) also increased with increasing V DS ; however, the observed J G was three orders of magnitude lower than J DS . Carriers cannot be injected in a gate electrode with increasing positive gate voltage unless the gate voltage exceeds the breakdown voltage.…”

“…Several groups have reported vertical-type organic transistors such as polymer grid transistors, organic a Email: fukagawa.h-fe@nhk.or.jp b Present address: Tokyo University of Science, Suwa, 5000-1 Toyohira, Chino-city, Nagano, 391-0292, Japan c Present address: Tohoku University, 6-6-05 Aramaki Aza Aoba, Aoba-ku, Sendai, 980-8579, Japan d Present address: Yamagata University, Research Center for Organic Electronics, 4-3-16 Jonan, Yonezawa, Yamagata 992-8510, Japan static induction transistors (SITs), metal-base organic transistors (MBOTs), space-charge-limited transistors (SCLTs), patterned electrode vertical organic field effect transistor (PE-VOFET) and permeable-base transistor (PMBT) to realize a short channel. [15][16][17][18][19][20][21][22][23][24][25][26] However, the relationship between the crystalline axis of the organic film and the carrier transport direction has not been examined for vertical-type organic transistors. If the planar molecules are oriented with the molecular plane parallel to the substrate in a vertical-type organic transistor, the carrier transport direction can easily be aligned with the π-π stacking direction of the organic film.…”

“…5,9,10 In addition to planar OTFTs, vertical-type organic transistors have been reported in recent years. [15][16][17][18][19][20][21][22][23][24][25][26] The vertical structure is considered promising for attaining high-current and low-voltage operation, in which the carriers flow across the thin film in the vertical direction, perpendicular to the film plane, with short channel paths having lengths corresponding to the semiconductor film thickness. Several groups have reported vertical-type organic transistors such as polymer grid transistors, organic a Email: fukagawa.h-fe@nhk.or.jp b Present address: Tokyo University of Science, Suwa, 5000-1 Toyohira, Chino-city, Nagano, 391-0292, Japan c Present address: Tohoku University, 6-6-05 Aramaki Aza Aoba, Aoba-ku, Sendai, 980-8579, Japan d Present address: Yamagata University, Research Center for Organic Electronics, 4-3-16 Jonan, Yonezawa, Yamagata 992-8510, Japan static induction transistors (SITs), metal-base organic transistors (MBOTs), space-charge-limited transistors (SCLTs), patterned electrode vertical organic field effect transistor (PE-VOFET) and permeable-base transistor (PMBT) to realize a short channel.…”

Influence of charge carrier injection at emitter electrode/emitter interface on the performance of metal-base organic transistors

“…The planar architecture, generally used in the organic field-effect transistors (OFETs), has disadvantages such as low current modulation and high operation voltage due to the limitation of channel length and the low carrier mobility of the organic materials [6] . Therefore, several vertical OTFTs, including field-effect and non-fieldeffect transistors have been proposed, which have high current modulation with lower operation voltages resulting from the shorter pathways for carrier transport compared with the planer OFETs [7][8][9][10][11][12][13][14][15][16][17] .One of the most promising vertical structures is the metalbase organic transistor (MBOT), which employs an ultrathin metal layer (the base) sandwiched between two semiconductors (the emitter and the collector) [18] . In such a device, the emitter-base junction (forward-biased) and the base-collector junction (reverse-biased) are back-to-back Schottky diodes in asymmetrical configuration, i.e., the barrier height of the emitter-base junction is larger than that of the basecollector junction for the injected charge carriers from the emitter, and the two diodes are completely separated electrically by the fully covered base metal film [15,18] .…”

“…The planar architecture, generally used in the organic field-effect transistors (OFETs), has disadvantages such as low current modulation and high operation voltage due to the limitation of channel length and the low carrier mobility of the organic materials [6] . Therefore, several vertical OTFTs, including field-effect and non-fieldeffect transistors have been proposed, which have high current modulation with lower operation voltages resulting from the shorter pathways for carrier transport compared with the planer OFETs [7][8][9][10][11][12][13][14][15][16][17] .…”