The type-II multiple quantum well (MQW) structure is prepared and introduced into green organic green light-emitting diodes consisting of 4,40-bis-[N-(naphthyl)-N-phenyl-amino]biphenyl (a-NPD) and tris-(8-hydroxyquinolinato)-aluminum (Alq3). The quantum well (QW) and wall are fabricated by 4,40 ,400-tris-(3-methylphenylphenylamino)triphenylamine (m-MTDATA) and a-NPD, respectively. The device pe...

In recent years, the developments in the OLEDs have gradually reached very advantageous of existence. These advantageous characteristics include self-luminous, wide viewing angle and low power consumption, etc. which make OLEDs very useful for numerous display applications and lighting devices. To effectively improve the characteristics of an OLEDs, there are many ways to be adopted. Such as: (...

sReceived 11 February 2005; accepted 27 April 2005; published online 20 June 2005d Bright green electroluminescence with luminance up to 2800 cd/m2 is reported from indium-tin-oxide/SiO2:Tb/Si metal-oxide-semiconductor devices. The SiO2:Tb 3+ gate oxide was prepared by thermal oxidation followed by Tb+ implantation. Electroluminescence and photoluminescence properties were studied with variatio...

We have synthesized nanoparticles of ZnS doped with Mn for potential use as cathodoluminescent phosphors in field-emission displays ~FEDs!. We show that the cathodoluminescent efficiency of particles <100 nm in diameter is within 40% of that of a commercial ~micron-sized! phosphor when the electron-beam energy ranges between 500 and 3500 eV. The nanoparticles exhibit less current saturation tha...

Luminous efficacy of radiation (LER) is one of the multiplicative factors affecting the wall‐plug efficiency of a light source. In order to maximize it, it is important to keep the spectral content of the lamp in a small region around 555 nm. However, doing so limits the color span that the source can correctly reproduce. Obviously, whether one determines to prioritize energy efficiency over co...

High-brightness blue and green light-emitting diodes ~LEDs! based on II–VI double heterostructures ~DHs! have been successfully grown by molecular-beam epitaxy ~MBE! on ~100! ZnSe substrates. These LED structures consist of a 500–1000 Å thick active region of undoped blue-emitting Zn0.9Cd0.1Se/ZnSe multiple quantum wells or a green-emitting ZnTe0.1Se0.9 single quantum well sandwiched between a ...

We have used triphenyldiamine side-group polymers as hole transport layers in multilayer organic light-emitting diodes using 8-hydroxyquinoline aluminum (Alq3) as an emission layer. The device efficiency systematically increases as the ionization potential of the hole transport layer is shifted further from the work function of the indium–tin–oxide anode. We attribute this trend to better balan...

Standard accretion disk theory is formulated which is based on the local heat balance. The energy produced by a turbulent viscous heating is supposed to be emitted to the sides of the disc. Sources of turbulence in the accretion disc are connected with nonlinear hydrodynamic instability, convection, and magnetic field. In standard theory there are two branches of solution, optically thick, and ...

Most LED manufacturers use units of luminous intensity (cd) for the measurement and classification of LED brightness. For numerous LED types, this procedure is reliable and reproducible. However, for LEDs with narrow emission angle characteristics, this method is inadequate. This application note describes the procedures for measuring luminous intensity, partial flux and luminous flux, along wi...