Ultra-Wide Band Gap GaO-on-SiC MOSFETs.

Ultra-wide band gap semiconductor devices based on β-phase gallium oxide (GaO) offer the potential to achieve higher switching performance and efficiency and lower manufacturing cost than that of today's wide band gap power electronics. However, the most critical challenge to the commercialization of GaO electronics is overheating, which impacts the device performance and reliability. We fabricated a GaO/4H-SiC composite wafer using a fusion-bonding method.

GaO-on-SiC Composite Wafer for Thermal Management of Ultrawide Bandgap Electronics.

β-phase gallium oxide (GaO) is an emerging ultrawide bandgap (UWBG) semiconductor ( ∼ 4.8 eV), which promises generational improvements in the performance and manufacturing cost over today's commercial wide bandgap power electronics based on GaN and SiC. However, overheating has been identified as a major bottleneck to the performance and commercialization of GaO device technologies.

Hysteretic Photochromic Switching (HPS) in Doubly Doped GaN(Mg):Eu-A Summary of Recent Results.

Europium is the most-studied and least-well-understood rare earth ion (REI) dopant in GaN. While attempting to increase the efficiency of red GaN light-emitting diodes (LEDs) by implanting Eu⁺ into p-type GaN templates, the Strathclyde University group, in collaboration with IST Lisbon and Unipress Warsaw, discovered hysteretic photochromic switching (HPS) in the photoluminescence spectrum of doubly doped GaN(Mg):Eu. Our recent work, summarised in this contribution, has used time-, temperature- and light-induced changes in the Eu intra-4 shell emission spectrum to deduce the microscopic nature of the Mg-Eu defects that form in this material.

Transformation of 2D group-III selenides to ultra-thin nitrides: enabling epitaxy on amorphous substrates.

The experimental realization of two-dimensional (2D) gallium nitride (GaN) has enabled the exploration of 2D nitride materials beyond boron nitride. Here we demonstrate one possible pathway to realizing ultra-thin nitride layers through a two-step process involving the synthesis of naturally layered, group-III chalcogenides (GIIIC) and subsequent annealing in ammonia (ammonolysis) that leads to an atomic-exchange of the chalcogen and nitrogen species in the 2D-GIIICs. The effect of nitridation differs for gallium and indium selenide, where gallium selenide undergoes structural changes and eventual formation of ultra-thin GaN, while indium selenide layers are primarily etched rather than transformed by nitridation.

Accuracy of a first-generation intravenous blood glucose monitoring system in subjects with diabetes mellitus: a multicenter study.

Background: Hyperglycemia and hypoglycemia in hospitalized patients have been associated with increased morbidity and mortality. Improvements in glucose monitoring technology may be helpful in the clinical management of critically ill patients with abnormal glucose levels. A first-generation intravenous blood glucose monitoring (IVBG) system was developed to facilitate glycemic control therapy in hospitalized patients.

Universal phonon mean free path spectra in crystalline semiconductors at high temperature.

Thermal conductivity in non-metallic crystalline materials results from cumulative contributions of phonons that have a broad range of mean free paths. Here we use high frequency surface temperature modulation that generates non-diffusive phonon transport to probe the phonon mean free path spectra of GaAs, GaN, AlN, and 4H-SiC at temperatures near 80 K, 150 K, 300 K, and 400 K. We find that phonons with MFPs greater than 230 ± 120 nm, 1000 ± 200 nm, 2500 ± 800 nm, and 4200 ± 850 nm contribute 50% of the bulk thermal conductivity of GaAs, GaN, AlN, and 4H-SiC near room temperature.

Extended use of a new continuous glucose monitoring system with wireless data transmission in children with type 1 diabetes mellitus.

Background: A new continuous glucose monitoring system (CGMS Datalogger, Medtronic MiniMed, Northridge, CA) potentiates extended sensor use by eliminating the cable connection to a monitor and by being waterproof. We evaluated the performance, safety, and patient tolerance of using the CGMS for 7 continuous days in children with type 1 diabetes mellitus who were encouraged to participate fully in their usual sports and activities in their home environment.

Methods: Twenty pediatric subjects (12.