The Convected Scheme (CS) is a family of `forward-trajectory' semi-Lagrangian schemes for the numerical solution of transport equations (most often the Boltzmann equation), which uses a method of characteristics in an integral form to project an initial `moving cell' (MC) forward to a group of final cells.The main drawback of the CS to date has been its high numerical diffusion in physical space, because of the 2nd order remapping that takes place at the end of each time step. A `long-lived moving cell' version of the CS was able to suppress such a numerical diffusion, but at the expense of reduced numerical efficiency and increased memory requirement. Recently a high order cell-centered version of the CS was proposed, suitable for the kinetic simulation of neutral gas flows, which is 4th order accurate in space, while retaining the desirable properties of the CS. This was achieved by compensating the remapping error via a `small correction' to the final position of the MC prior to remapping. Here a similar procedure is used to obtain a high-order face centered version of the CS, which is suitable for the solution of the Boltzmann-Poisson system for a low temperature plasma. Such a scheme is 3rd-order accurate in space, conservative, positivity preserving, very simple to implement and fast to run. The convergence properties of the new high-order scheme, as well as its numerical stability, are analyzed in classical electrostatic test-cases. The impact of the reduced numerical diffusion in space is discussed in detail. When applied to kinetic simulations of plasmas, the CS is also affected by numerical diffusion in velocity. Recent advances are presented and preliminary results are shown, for a scheme which is high-order accurate in both space and velocity.

We have fabricated a highly efficient inverted bottom-emission organic light-emitting diode (IBOLED) based on an indium-tin oxide (ITO) bottom cathode deposited with an ultrathin 1 nm layer of Mg to promote electron injection. The threshold voltage of this IBOLED with a structure of ITO/Mg/Alq(3)/NPB/WO3/Al was 4.2V and an efficiencies of 4.66cd/A and 1.51 1m/W were achieved at an operational voltage of 8.9 V and a brightness of 940 cd/m(2). In comparison with an ITO/Alq(3) bottom cathode composition, a reduction in drive voltage from 13.8 to 7.8 V in voltage was obtained at 1 mA/cm(2). A charge-transfer dipole model is proposed to rationalize the enhanced electron injection.

The authors report the development of highly efficient and stable C545T doped green fluorescent Alq3 inverted bottom-emission organic light emitting device (OLED), with a device configuration of ITO∕Mg∕Cs2O:Bphen∕Alq3∕C545T:Alq3∕NPB∕WO3∕Al, that achieved a maximum current efficiency of 23.7cd∕A and a power efficiency of 12.4lm∕W which are two times better than those of the conventional OLED. At a brightness level of 100cd∕m2, the device required driving current density only as low as 0.5mA∕cm2 at a driving voltage of only 5.0V and its half-lifetime T1∕2 in excess of 104000h.

We report efficient inverted transparent blue OLEDs (ITOED) with an hole injection layer prepared by co-evaporation of WO3 with NPB, which achieved a total current efficiency 0 10.7 cd/A at 20 mA/cm(2) with light emits from both ITO bottom cathode and Au top anode in about 3:1 ratio.

The authors have fabricated and compared highly efficient inverted white organic light-emitting devices (WOLEDs) with a single emission layer (SEL) and with a multiemission layer (MEL). The efficiency levels of the WOLEDs with a SEL and a MEL achieved 13.0cd∕A, 10.6lm∕W and 11.3cd∕A, 7.3lm∕W, respectively. The projected half lifetime of a SEL device under an initial luminance of 400cd∕m2 is expected to be over 34000h, which is five times better than that of a MEL device of 6350h. The Commission International de l’Eclairage coordinates of a SEL device are not affected by aging.

Stable inverted bottom-emitting organic light-emitting diodes (IBOLEDs) have been investigated by inserting n-type Cs2O dopant between indium-tin oxide bottom cathode and Alq3, the combination of which not only improved the morphology of organic layer but enhanced the lifetime of the IBOLED. This n-type doped IBOLED achieved efficiencies of 5.2cd∕A and 2.0lm∕W at 20mA∕cm2. The 20% decay lifetime (t80) of Cs2O doped IBOLED is 270h which is about 1.7 times more stable than that of the conventional OLED (160h) and 2.5 times of Li doped IBOLED (104h).