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Operational improvement of AlGaN/GaN HEMT on SiC substrate with the amended depletion region

Highlights •AlGaN/GaN HEMT on SiC substrate is presented to improve the electrical operation. •The depletion region of structure is amended using a multiple recessed gate. •A gate structure is proposed to be able to control the thickness of the channel. •RF parameters are considered and are improved. In this paper, a high performance AlGaN/GaN [...]

2015-08-07 , Read more...

Barrier controlled carrier trapping of extended defects in CdZnTe detector

Highlights •The barrier controlled trapping model was developed around extended defects. •Electron mobility and E-field distribution were distorted by space charge depletion region. •Extended defects act as a recombination-activated region. •The relationships between extended defects and detector performance were established. Transient current techniques using alpha particle source were utilized to study the influence of [...]

2015-07-31 , , , Read more...

Temperature-dependent electrical characterization of high-voltage AlGaN/GaN-on-Si HEMTs with Schottky and ohmic drain contacts

Highlights •We fabricated HV AlGaN/GaN-on-Si HEMTs with Schottky and ohmic drain electrodes. •We examine impact of temperature on the electrical parameters of fabricated devices. •The use of Schottky drain contacts increase the breakdown voltage from 505 to 900 V. •The SD-HEMTs are characterized by lower increase of Ron with increasing temperature. Abstract In this work [...]

2015-07-21 , , Read more...

Electrical and structural properties of GaN films and GaN/InGaN light-emitting diodes grown on porous GaN templates fabricated by combined electrochemical and photoelectrochemical etching

Electrical and structural properties of GaN films and GaN/InGaN light-emitting diodes grown on porous GaN templates fabricated by combined electrochemical and photoelectrochemical etching Highlights •Porous GaN template was prepared by electrochemical and photoelectrochemical etching scheme. •InGaN/GaN light-emitting diode (LED) structure was overgrown on the etched GaN template. •Overgrown GaN films and LEDs showed [...]

2015-07-14 Read more...

Plastically deformed Ge-crystal wafers as elements for neutron focusing monochromator

Plastically deformed Ge-crystal wafers that have the cylindrical shape with a large curvature were characterized by neutron diffraction. The box-type rocking curve of Bragg reflection with the angular width of Γbox≃2° in FWHM, which is observable in the monochromatic neutron diffraction, results in an enhancement in the angle-integrated intensity (Iθ). Besides,Iθ efficiently [...]

2015-07-09 Read more...

High-power broad-area InGaNAs/GaAs quantum-well lasers in the 1200 nm range

High-power broad-area InGaNAs/GaAs quantum-well (QW) edge-emitting lasers on GaAs substrates in the 1200 nm range are reported. The epitaxial layers of the InGaNAs/GaAs QW laser wafers were grown on n+-GaAs substrates by using metal-organic chemical vapor deposition (MOCVD). The thickness of the InGaNAs/GaAs QW layers is 70 Å/1200 Å. The indium content [...]

2015-07-07 , , , Read more...

Porous silicon optical microcavity biosensor on silicon-on-insulator wafer for sensitive DNA detection

Silicon-on-insulator (SOI) wafer is one of the most appealing platforms for optical integrated circuit with the potential to realize high performance Ultra Large Scale Integration (ULSI) and device miniaturization. In this work, based on simulations to obtain appropriate optical properties of a porous silicon microcavity (PSM), we successfully fabricated [...]

2015-05-23 , Read more...

Aberration-corrected transmission electron microscopy analyses of GaAs/Si interfaces in wafer-bonded multi-junction solar cells

Highlights •Aberration-corrected TEM and EELS reveal structural and elemental profiles across GaAs/Si bond interfaces in wafer-bonded GaInP/GaAs/Si – multi-junction solar cells. •Fluctuations in elemental concentration in nanometer-thick amorphous interface layers, including the disrubutions of light elements, are measured using EELS. •The projected widths of the interface layers are determined on the atomic [...]

2015-05-19 , Read more...