With the aid of depth-resolved confocal microscopy, the optical crosstalk phenomenon in GaN-based micro-pixel light-emitting diodes (m-LEDs) on Si substrates are thoroughly investigated and compared with its counterpart on sapphire substrate. Noticeable optical crosstalk is invariably present in GaNon-sapphire devices as the thick transparent sapphires beneath the m-LEDs serve as optical wavegu...

Devices such as sensors, actuators, or micro-electromechanical systems (MEMS) are obtained by a variety of microfabrication processes. Many these processes influence the material introduction strain and defects, which may affect final device's performance reliability. Indeed, controlling materials' status during is fundamental for process optimization itself guaranteeing highest devices perform...

Introduction : Gallium Nitride (GaN) is a very interesting and highly promising material system for both optical and microwave high-power electronic applications. The large band gap of GaN makes it a suitable choice for high frequency applications. Thermal evaluation is pivotal in the design, characterization and reliability evaluation of semiconductor devices and circuits. The role it plays is...

This paper presents the synthesis of wafer scale 3D ZnO nanoarchitectures composed of an array of 1D nanowires (NWs) embedded in 2D nanowalls by the vapor−liquid−solid (VLS) method. The effects of oxygen concentration and growth temperature on the density of nanostructures were studied. The 3D ZnO nanostructures were synthesized on c-plane GaN-on-sapphire substrate utilizing high purity ZnO pow...

We report the reduction of the thermal lensing in cryogenic sapphire mirrors, which is planed to be used in the Large scale Cryogenic Gravitational wave Telescope (LCGT) project. We measured three key parameters of sapphire substrate for thermal lensing at cryogenic temperature. They are optical absorption coefficient, thermal conductivity and temperature coefficient of refractive index at cryo...

IBA methods were applied to measure elemental depth profiles of precursors and superconducting MgB2 thin films deposited on glassy carbon (Good Fellows) and sapphire (Al2O3) substrates. For each type of substrates we obtained a pair of samples i.e. one amorphous precursor and one superconducting film which were then characterized. A He beam was used to bombard both, precursors and superconducti...

We report on the effects of substrate, starting material, and temperature on the growth of MoS(2) atomic layers by thermal vapor sulfurization in a tube-furnace system. With Mo as the starting material, atomic layers of MoS(2) flakes are obtained on sapphire substrates while a bell-shaped MoS(2) layer, sandwiched by amorphous SiO(2), is obtained on native-SiO(2)/Si substrates under the same sul...

There is a growing need in space and environmental research applications for dual-mode, passive and active 2D and 3D ladar imaging methods. To fill this need, an advanced back-illuminated avalanche photodiode (APD) design is presented based on crystallographically etched (100) epitaxial silicon on R-plane sapphire (SOS), enabling single photon sensitive, solid-state focal plane arrays (FPAs) wi...

The effect of Si doping on the strain and microstructure in GaN films grown on sapphire by metalorganic chemical vapor deposition was investigated. Strain was measured quantitatively by x-ray diffraction, Raman spectroscopy, and wafer curvature techniques. It was found that for a Si concentration of 2310 cm, the threshold for crack formation during film growth was 2.0 mm. Transmission electron ...