Low driving voltage in an organic light-emitting diode using MoO_3/NPB multiple quantum well structure in a hole transport layer

The driving voltage of an organic light-emitting diode（OLED） is lowered by employing molybdenum trioxide（MoO3）/N,N＇-bis（naphthalene-1-yl）-N,N＇-bis（phe-nyl）-benzidine（NPB） multiple quantum well（MQW） structure in the hole transport layer.For the device with double quantum well（DQW） structure of ITO/[MoO3（2.5 nm）/NPB（20 nm）]2/Alq3（50 nm）/LiF（0.8 nm）/Al（120 nm）],the turn-on voltage is reduced to 2.8 V,which is lowered by 0.4 V compared with that of the control device（without MQW structures）,and the driving voltage is 5.6 V,which is reduced by 1 V compared with that of the control device at the 1000 cd/m2.In this work,the enhancement of the injection and transport ability for holes could reduce the driving voltage for the device with MQW structure,which is attributed not only to the reduced energy barrier between ITO and NPB,but also to the forming charge transfer complex between MoO3 and NPB induced by the interfacial doping effect of MoO3.

Realization of an 850V High Voltage Half Bridge Gate Drive IC with a New NFFP HVI Structure

A NFFP HVI structure which implements high breakdown voltage without using additional FFP and process steps is proposed in this paper. An 850 V high voltage half bridge gate drive IC with the NFFP HVI structure is experimentally realized using a thin epitaxial BCD process. Compared with the MFFP HVI structure, the proposed NFFP HVI structure shows simpler process and lower cost. The high side offset voltage in the half bridge gate drive IC with the NFFP HVI structure is almost as same as that with the self-shielding structure.

Three-level inverter configuration with common mode voltage elimination for induction motor drive (To continue)

The multiplicity of vector combinations for vectors of combined three-level inverters plays an important role, when deciding on the modulation scheme, to obtain minimum switching per inverter vector change, as described in the next Section. This is not possible with reduced common-mode three-level inverter structure, obtained with a five-level cascaded H-bridge configuration, as the space vectors locations do not exhibit multiplicity. Moreover, the proposed configuration requires only two power supplies, whereas the scheme with the five-level H-bridge configuration requires six isolated power supplies.

Three-level inverter configuration with common mode voltage elimination for induction motor drive

The multiplicity of vector combinations for vectors of combined three-level inverters plays an important role, when deciding on the modulation scheme, to obtain minimum switching per inverter vector change, as described in the next Section. This is not possible with reduced common-mode three-level inverter structure, obtained with a five-level cascaded H-bridge configuration, as the space vectors locations do not exhibit multiplicity. Moreover, the proposed configuration requires only two power supplies, whereas the scheme with the five-level H-bridge configuration requires six isolated power supplies.

Derivation of Multilevel Voltage Source Converter Topologies for Medium Voltage Drives

Multilevel voltage source converters(MLVSCs)have been widely applied in the medium voltage drive(MVD)industry.The performance of a MVD system is strongly dependent on the utilized topology.As of today,many interesting topologies have been proposed and evaluated in literature.In addition to proposing new topologies,another important research topic is the MLVSC topology derivation.In this paper,two topology derivation principles,i.e.horizontal conformation principle and vertical conformation principle,are proposed from the standpoint of modularity.In both principles,a MLVSC topology can be considered as a certain combination of one base switching cell and several module switching cells.With the proposed principle,the derived topology will naturally have modularity,which is favorable in practical applications.In addition,voltage level extension based on cascaded H-bridge building blocks(HBBBs)is also introduced.The challenging issues faced by the emerging topologies for MVD applications are also discussed.It is hoped that this paper can provide a new perspective on the MLVSC topology derivation and inspire new topologies in the future.

The effects of coil-stretch transition behavior of polyfluorene inks on single droplet formation during inkjet printing

For drop-on-demand(DOD)inkjet printing,stable and single ink droplet fo rmation without satellite dots is the key to improve the print quality.The formation of stable and single droplet is influenced by filament break up and the polymer chain’s coil-stretch transition behavior.In this paper,the droplet formation behaviors of polyfluorene(PFO)ink at various driving voltages(V),polymer chain’s coil-stretch transition mechanism and its effects on single ink droplet formation are investigated.It indicates that when 5863 V,Wi>0.5,the PFO molecular chain is stretched because of the high hydrodynamic forces,resulting unwanted satellite droplets.When 55<V<58V,the droplet shrinks into the nozzle,which indicates that the kinetic energy supplied by the deformation of the piezoelectric transducer isn't enough to force thedroplet to be jetted from the nozzle.