Bess G. Singidas's research while affiliated with University of the Philippines and other places

Publications (7)

Article
The interplay between intrinsic grain and inter-grain effects at the superconducting state defines the behavior of bulk high-temperature superconductors. In this work, we use DC resistivity and AC magnetic susceptibility measurements to show how the intrinsic and inter-grain properties influence the intergrain phase coherence and flux dynamics of B...
Article
Graphene–semiconductor junction interface states influence the carrier recombination processes in emerging optoelectronic devices. The large density of interface states in the graphene–GaAs junction is partly formed by oxidation in air of the GaAs surface. A graphene transfer presented herein reduces the arsenic species in the GaAs oxide and mainta...
Article
In realizing zinc oxide (ZnO) scintillator applications, we assess the optical damage and investigate the recovery of hydrogen-ion (H-ion) and deuterium-ion (D-ion) plasma-irradiated bulk ZnOsingle crystals. Hydrothermal-grown bulk crystals are irradiated with H-ion and D-ion beams with 1 keV energy and ∼1020 m−2 s−1 flux. After irradiation, the si...
Article
Hydrothermal-grown bulk zinc oxide (ZnO) single crystals are investigated before and after 1-keV hydrogen-ion and deuterium-ion plasma irradiation. A decrease in optical transmittance, red-shifting of ultraviolet (UV) emission peaks, and shortening of UV emission lifetimes are observed from the bulk crystals immediately after irradiation. The resul...
Article
Full-text available
We investigate the optical transmittances of ion-irradiated sapphire crystals as potential vacuum ultraviolet (VUV) to near-infrared (NIR) window materials of fusion reactors. Under potential conditions in fusion reactors, sapphire crystals are irradiated with hydrogen (H), deuterium (D), and helium (He) ions with 1-keV energy and ∼ 10²⁰-m⁻² s⁻¹ fl...
Article
The AC susceptibility () of YBCO with and without intergrain coupling was measured in AC fields within 0.13 and 3.72 mT and frequencies from 20 Hz to 12.8 kHz. Intergrain coupling was eliminated by dispersing the powder in insulating varnish. For the coupled and uncoupled grains, the transition near TC is field independent, indicating that the fiel...

Citations

... Using quantum dots (QDs), Jianghong Wu et al. increased the efficiency of Graphene-based electronic systems [25]. B. G. Singidas et al. reduced the density of surface states at the Graphene/GaAs junction using the passivation layer between Graphene and GaAs [26]. ...
... TiO 2 has been widely used for photovoltaics, photocatalysts and energy storage devices, because of its high refractive index and unique photooxidation feature [13]. These prototypical wide-bandgap semiconductors are also good candidate for application in harsh environments, such as low earth satellite orbit and fusion reactors [14], facing high fluences of various particles radiation. Therefore, it is crucial to investigate the radiation damage as well as the methodology to enhance the radiation resistance of such functional semiconductors. ...
... Because of these properties, ZnO bulk crystals and thin films have been widely studied for numerous optoelectronic applications. For example, ZnO bulk crystals have been suggested as potential scintillators for radiation detection as the crystals exhibit bright luminescence, fast response time, and radiation hardness [2][3][4][5]. ZnO thin films are also promising candidate materials for transparent electrodes because of the thin films' conductivity for visible-blind devices [1,6,7]. Moreover, ZnO-based layers can be used as sensors or catalysts for industrial applications [8,9]. ...
... Проблема очистки сапфировых окон от загрязнений существует в самых разнообразных плазменных [11] и высокотемпературных вакуумных установках. ...
... A large aspect ratio is highly ideal for improving the sensitivity of the nanowires for real-time monitoring for sensor applications [1][2][3][4][5][6][7]. As a prospective future work, the micromanipulation and harvesting of iron oxide nanowires using the cantilevers of an atomic force microscope should be performed to isolate iron oxide nanowires for possible electronic applications (which our group has successfully demonstrated in the case of hydrothermally prepared ZnO nanowires exhibiting highly suitable scintillation properties, see [42,43]). (>10.0 µ m) microspheres are necessary to provide a sufficient supply of Fe during the carbothermal process for the growth of iron oxide nanowires. To illustrate the role of the carbon-rich environment in the self-assembly of iron oxide nanostructures, a reference Fe microsphere was oxidized in air (or without carbon) as shown in Figure 3f. ...
... However, T p is broadened and shifted to the lower temperature with the increase of graphene nanoparticles in Y123 samples due to the weakening of intergranular coupling between grains, as shown in Figure 4 [48]. This decrement may be due to some defects at the grain boundaries such as grain disorientation, twin boundaries and vacancies that can act as weak links, therefore disturbing the T p and pinning forces [49]. The broad width of χ" might also be caused by the second superconducting transition of the secondary phase. ...