Highly balanced ambipolar mobilities with intense electroluminescence in field-effect transistors based on organic single crystal oligo(p-phenylenevinylene) derivatives

Tuning of threshold voltage by interfacial carrier doping in organic single crystal ambipolar light-emitting transistors and their bright electroluminescence

“…In our previous work, we fabricated bright ambipolar LE-OFETs based on highly luminescent unsubstituted oligo͑p-phenylenevinylene͒ ͑OPV͒ single crystals and revealed that an increase in conjugation length from three phenylene rings ͑P3V2͒ to four phenylene rings ͑P4V3͒ enhanced the electron mobility by up to one order of magnitude ͑to e Ͼ 10 −1 cm 2 / V s͒ while keeping a high hole mobility of h Ͼ 10 −1 cm 2 / V s. 11 However, for a current-driven organic laser, the maximum current density in the ambipolar region remains too low ͑ϳ6 A/ cm 2 assuming a 10 nm carrier accumulation layer thickness͒. 11 In this study, we achieve injection of high current density into the recombination zone by decreasing carrier injection barriers at the metal/organic interface by interfacial carrier doping based on electron transfer from an organic single crystal into a molybdenum oxide ͑MoO x ͒ layer.…”

“…11 In this study, we achieve injection of high current density into the recombination zone by decreasing carrier injection barriers at the metal/organic interface by interfacial carrier doping based on electron transfer from an organic single crystal into a molybdenum oxide ͑MoO x ͒ layer. Interfacial carrier doping in organic semiconductors has been successively demonstrated using not only organic electron accepting materials such as tetrafluorotetracyanoquinodimethane 12 but also metal oxides such as MoO x .…”

Control of Efficiency, Brightness, and Recombination Zone in Light‐Emitting Field Effect Transistors

“…The split gate (SG) structure enables independent control of the injection of electrons and holes, [11] and therefore enables control of the electroluminescence. [13][14] In order to fully utilize the benefit of controlled injection in SG-LEFETs, we have used an ambipolar light-emitting conjugated polymer, poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-(benzo [2,1,3] thiadiazol-4,7-diyl)], F8BT, as the semiconducting material in the channel. A single F8BT layer with symmetric Au source and drain contacts can respond to both negative and positive gate bias and has relatively high photoluminescence quantum efficiency (PLQY ≈ 50 to 60%).…”

Surface‐light‐emitting transistors based on vertical‐type metal‐base organic transistors

“…Since the first organic light-emitting transistor using an OFET structure reported by Hepp et al, 23 many reports on light-emitting OFETs have been published using a fluorescent organic semiconductor, [24][25][26] a combination of p-type and n-type materials, [27][28][29] light-emitting polymer, 30,31 and single crystals. [32][33][34][35] These devices, however, require special materials that demonstrate both high fluorescent quantum yield and high crystallinity, leading to high mobility. In addition, light-emission results from the recombination of channel holes accumulated by the gate voltage and injected electrons from the drain as shown in Fig.…”