排序方式: 共有42条查询结果,搜索用时 15 毫秒
1.
Genoe J. Van Hoof C. Van Roy W. Smet J.H. Fobelets K. Mertens R.P. Borghs G. 《Electron Devices, IEEE Transactions on》1991,38(9):2006-2012
Capacitances in a double-barrier tunneling structure are calculated for the specific sequential electron tunneling regime. Starting from Luryi's (1988) definition of quantum capacitance, the authors model the charge accumulation in the well during the tunneling process using the Fermi-Dirac distribution. Analytical formulas for the total capacitance and conductance are derived. A complete small-signal model is proposed that demonstrates the external capacitance and conductance of the structure and its frequency behavior. The authors show both theoretically and experimentally that the capacitance in a tunneling structure is both bias- and frequency-dependent 相似文献
2.
S. Schols S. Verlaak C. Rolin D. Cheyns J. Genoe P. Heremans 《Advanced functional materials》2008,18(1):136-144
The cover shows an organic light‐emitting diode with remote metallic cathode, reported by Sarah Schols and co‐workers on p. 136. The metallic cathode is displaced from the light‐emission zone by one to several micrometers. The injected electrons accumulate at an organic heterojunction and are transported to the light‐emission zone by field‐effect. The achieved charge‐carrier mobility and in combination with reduced optical absorption losses because of the remoteness of the cathode may lead to applications as waveguide OLEDs and possibly a laser structure. (The result was obtained in the EU‐funded project “OLAS” IST‐ FP6‐015034.) We describe an organic light‐emitting diode (OLED) using field‐effect to transport electrons. The device is a hybrid between a diode and a field‐effect transistor. Compared to conventional OLEDs, the metallic cathode is displaced by one to several micrometers from the light‐emitting zone. This micrometer‐sized distance can be bridged by electrons with enhanced field‐effect mobility. The device is fabricated using poly(triarylamine) (PTAA) as the hole‐transport material, tris(8‐hydroxyquinoline) aluminum (Alq3) doped with 4‐(dicyanomethylene)‐2‐methyl‐6‐(julolindin‐4‐yl‐vinyl)‐4H‐pyran (DCM2) as the active light‐emitting layer, and N,N′‐ditridecylperylene‐3,4,9,10‐tetracarboxylic diimide (PTCDI‐C13H27), as the electron‐transport material. The obtained external quantum efficiencies are as high as for conventional OLEDs comprising the same materials. The quantum efficiencies of the new devices are remarkably independent of the current, up to current densities of more than 10 A cm–2. In addition, the absence of a metallic cathode covering the light‐emission zone permits top‐emission and could reduce optical absorption losses in waveguide structures. These properties may be useful in the future for the fabrication of solid‐state high‐brightness organic light sources. 相似文献
3.
Nanoimprint lithography is used to directly pattern the conjugated polymer semiconductor poly(3-hexylthiophene) (P3HT). We obtain trenches with aspect ratios up to 2 and feature sizes as small as 50?nm in this polymer. The application to organic solar cells is shown by creating an interpenetrated donor-acceptor interface, based on P3HT and N,N'-ditridecyl-3,4,9,10-perylenetetracarboxylic diimide (PTCDI-C(13)), deposited from the vapor phase to reduce shadow effects. A planarizing layer of spin-coated zinc oxide (ZnO) nanoparticles is used to reduce the roughness of the layer stack. The response of the photovoltaic devices follows the increased interface area, up to a 2.5-fold enhancement. 相似文献
4.
A. Yu. Zherebov A. N. Lachinov J. Genoe A. R. Tameev A. V. Vannikov 《Technical Physics Letters》2008,34(6):475-478
Experimental and theoretical data show that the phenomenon of bistable switching in thin films of poly(arylenephthalides)
(PAPs), which was reported previously, has an electronic nature and is related to the unique properties of PAP molecules.
This phenomenon has been studied in metal-PAP-metal and ITO-PAP-ITO structures (ITO = indium tin oxide) with various thicknesses
of the polymer film. First results are reported that demonstrate the principal possibility of using thin PAP films as a basis
for resistive nonvolatile electronic memory cells. These data show that the bistable switching is related primarily to the
electronic properties of the polymer film and is not influenced by the oxidation of electrodes and/or the growth of metal
filaments from the electrodes. 相似文献
5.
Cédric Rolin Karolien Vasseur Björn Niesen Myriam Willegems Robert Müller Sören Steudel Jan Genoe Paul Heremans 《Advanced functional materials》2012,22(23):5050-5059
Compared to traditional vacuum evaporation techniques for small organic molecules, organic vapor phase deposition (OVPD) possesses a extra processing parameter: the pressure of process gas Pch. Here, the influence of large Pch variations (from 0.1 mbar to atmospheric pressure) on pentacene thin film growth is explored. OVPD operation at higher Pch is characterized by lower carrier gas velocities and lower organic diffusivities. These result in an invariance of the material utilization efficiency over the entire pressure span and in an advantageous equilibrium evaporation regime in the source. An increase in Pch yields rough pentacene layers. Classical nucleation theory is applied to demonstrate how the pressure rise triggers homogeneous nucleation in the gas phase, causing the observed roughening. The use of lower deposition rates, higher dilution flow rates, and higher substrate temperatures result in the suppression of gas phase nucleation and the growth of smooth pentacene films at atmospheric pressure. Using these optimized conditions, state‐of‐the‐art pentacene thin film transistors with saturation mobilities above 0.9 cm2/Vs are reproducibly fabricated. p‐Type circuits are also made and a 19‐stage ring oscillator with a stage delay of 51 μs at a supply voltage of 15 V is demonstrated. 相似文献
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Azhar Fakharuddin Weiming Qiu Guillaume Croes Andrius Deviis Rokas Gegevi
ius Alexander Vakhnin Cedric Rolin Jan Genoe Robert Gehlhaar Andrey Kadashchuk Vidmantas Gulbinas Paul Heremans 《Advanced functional materials》2019,29(37)
Perovskite light emitting diodes (PeLEDs) have reached external quantum efficiencies (EQEs) over 21%. Their EQE, however, drops at increasing current densities (J) and their lifetime is still limited to just a few hours. The mechanisms leading to EQE roll‐off and device instability require thorough investigation. Here, improvement in EQE, EQE roll‐off, and lifetime of PeLEDs is demonstrated by tuning the balance of electron/hole transport into a mixed 2D/3D perovskite emissive layer. The mixed 2D/3D perovskite layer induces exciton confinement and beneficially influences the electron/hole distribution inside the perovskite layer. By tuning the electron injection to match the hole injection in such active layer, a nearly flat EQE for J = 0.1–200 mA cm?2, a reduced EQE roll‐off until J = 250 mA cm?2, and a half‐lifetime of ≈47 h at J = 10 mA cm?2 is reached. A model is also proposed to explain these improvements that account for the spatial electron/hole distributions. 相似文献
9.
Power saving through state retention in IGZO‐TFT AMOLED displays for wearable applications 下载免费PDF全文
Soeren Steudel Jan‐Laurens P.J. van der Steen Manoj Nag Tung Huei Ke Steve Smout Thijs Bel Karin van Diesen Gerard de Haas Joris Maas Joris de Riet Madelon Rovers Roy Verbeek Yen‐Yu Huang Shin‐Chuan Chiang Marc Ameys Florian De Roose Wim Dehaene Jan Genoe Paul Heremans Gerwin Gelinck Auke Jisk Kronemeijer 《Journal of the Society for Information Display》2017,25(4):222-228
We present a qHD (960 × 540 with three sub‐pixels) top‐emitting active‐matrix organic light‐emitting diode display with a 340‐ppi resolution using a self‐aligned IGZO thin‐film transistor backplane on polyimide foil with a humidity barrier. The back plane process flow is based on a seven‐layer photolithography process with a CD = 4 μm. We implement a 2T1C pixel engine and use a commercial source driver IC made for low‐temperature polycrystalline silicon. By using an IGZO thin‐film transistor and leveraging the extremely low off current, we can switch off the power to the source and gate driver while maintaining the image unchanged for several minutes. We demonstrate that, depending on the image content, low‐refresh operation yields reduction in power consumption of up to 50% compared with normal (continuous) operation. We show that with the further increase in resolution, the power saving through state retention will be even more significant. 相似文献
10.
Manoj Nag Ajay Bhoolokam Steve Smout Myriam Willegems Robert Muller Kris Myny Sarah Schols Marc Ameys Jan Genoe Tung Huei Ke Peter Vicca Tim Ellis Brian Cobb Abhishek Kumar Jan‐Laurens P. J. van der Steen Gerwin Gelinck Yusuke Fukui Koji Obata Guido Groeseneken Paul Heremans Soeren Steudel 《Journal of the Society for Information Display》2014,22(10):509-517
A process to make self‐aligned top‐gate amorphous indium‐gallium‐zinc‐oxide (a‐IGZO) thin‐film transistors (TFTs) on polyimide foil is presented. The source/drain (S/D) region's parasitic resistance reduced during the SiN interlayer deposition step. The sheet resistivity of S/D region after exposure to SiN interlayer deposition decreased to 1.5 kΩ/□. TFTs show field‐effect mobility of 12.0 cm2/(V.s), sub‐threshold slope of 0.5 V/decade, and current ratio (ION/OFF) of >107. The threshold voltage shifts of the TFTs were 0.5 V in positive (+1.0 MV/cm) bias direction and 1.5 V in negative (?1.0 MV/cm) bias direction after extended stressing time of 104 s. We achieve a stage‐delay of ~19.6 ns at VDD = 20 V measured in a 41‐stage ring oscillator. A top‐emitting quarter‐quarter‐video‐graphics‐array active‐matrix organic light‐emitting diode display with 85 ppi (pixels per inch) resolution has been realized using only five lithographic mask steps. For operation at 6 V supply voltage (VDD), the brightness of the display exceeds 150 cd/m2. 相似文献