1,720,987 research outputs found
Evaluation of static performance of optoelectronic semiconductor devices under X-rays irradiation
No full textInternational Conference on X-Rays and Related Techniques in Research and Industry (ICXRI 2010) jointly organized by Universiti Malaysia Perlis (UniMAP) and X-Ray Application Malaysia Society (XAPP), 9th - 10th June 2010 at Aseania Resort Langkawi, Malaysia.Nowadays, the space technology is becoming increasingly versatile and important. Most of the important technologies such as weather forecasting, remote sensing, navigation operations, satellite television, and telecommunications systems, as well as surveillance and command-and-control operations for national security purposes critically rely on space infrastructure. Consequently, these kinds of systems are subjected to the deleterious effects of the natural space radiation environment. Furthermore, there is a growing tendency in using commercial-off-the shelf (COTS) optoelectronic devices for replacing dedicated expensive radiation hardened photonics. Expanding photonic system into such environments requires a full understanding of the effects that ionizing radiation will have on the optoelectronic properties. In this research, optoelectronic devices consisted of an infrared light emitting diode and a phototransistor with no special handling or third party-packaging were irradiated to ionizing radiation utilizing x-rays. It was found that the devices under test (DUTs) undergo performance degradation in their functional parameters during exposure to x-rays. These damaging effects are depending on their current drives and also the Total Ionizing Dose (TID) absorbed. The TID effects by x-rays are cumulative and gradually take place throughout the lifecycle of the devices exposed to radiation
Evaluation of Static Performance of Optoelectronic Semiconductor Devices under X-Rays Irradiation
No full textIn this research, optoelectronic devices consisted of an infrared light emitting diode and a phototransistor with no special handling or third party-packaging were irradiated to ionizing radiation utilizing x-rays. It was found that the devices under test (DUTs) undergo performance degradation in their functional parameters during exposure to x-rays. These damaging effects are depending on their current drives and also the Total Ionizing Dose (TID) absorbed. The TID effects by x-rays are cumulative and gradually take place throughout the lifecycle of the devices exposed to radiation.</jats:p
Monte Carlo study of alpha (α) particles transport in nanoscale gallium arsenide semiconductor materials
No full textEffect of Al₂O₃, RHF, and RHA on gamma shielding and mechanical properties of TeO₂-Based glass using Phy-X/PSD
No full textRadiation attenuation behaviour of TeO₂–ZnO–Bi₂O₃–Na₂O–Er₂O₃ with the addition of Al₂O₃ nanoparticles (NP), rice husk fibre (RHF), and rice husk ash (RHA) was investigated using Phy-X/PSD software. The mass attenuation coefficients of the chosen glasses were measured from 0.015 to 3 MeV. The results showed that increasing the RHF concentration of the glasses or decreasing the Al₂O₃ component of the glass system enhances the mass attenuation coefficient of the material. At low energy, there is a significant difference between the mass attenuation coefficients values of the samples with the lowest and highest Al₂O₃ content, where the difference is 0.05118 cm2/g at 0.015 MeV. TZNERHF had higher mass attenuation coefficients (0.05402 cm2/g), and TZNETiAl8 had the highest mass attenuation coefficients, with a value of 0.05357 cm2/g at 1.173 MeV. The results showed a decreasing trend in the half-value layer (HVL), tenth value layer (TVL), and mean free path (MFP) when the density increased from 5.12555 to 5.23882 g/cm3 and attenuation ability improved. Subsequently, the influence of Al₂O₃ on Zeff values became more considerable as Zeff values increased. The shielding qualities of their glass samples are also superior to commercial window glass and common shielding concrete. Thus, the glass samples can be used with excellent advantage as radiation shielding materials. The findings showed that adding RHF and lower Al₂O₃ enhanced the studied samples' radiation shielding properties. The results show that the TZNERHF glass sample has the highest mechanical properties. Thus, the TZNERHF sample is better than the other glass samples
Composition Dependence Structural and Optical Properties of Silicon Germanium (SiχGe1−χ) Thin Films
Get PDFThis study investigates the structural and optical characteristics of Silicon Germanium (SiGe) thin films with varying compositions and annealing temperatures for potential use in electronic and optoelectronic devices. Si0.8Ge0.2 and Si0.9Ge0.1 films were deposited onto a high-temperature quartz substrate and annealed at 600 °C, 700 °C, and 800 °C before being evaluated using an X-Ray Diffractometer (XRD), Atomic Force Microscopy (AFM), and a UV-Vis Spectrometer for structural and optical properties. The results show that increasing the annealing temperature results in an increase in crystalline size for both compositions. The transmittance for Si0.8Ge0.2 decreases slightly with increasing temperature, while Si0.9Ge0.1 remains constant. The optical band gap for Si0.9Ge0.1 thin film is 5.43 eV at 800 °C, while Si0.8Ge0.2 thin film is 5.6 eV at the same annealing temperature. XRD data and surface analysis reveal significant differences between the band edges of SiGe nano-structure materials and bulk crystals. However, the possibility of a SiGe nano-crystal large band gap requires further investigation based on our study and related research works
Range distribution and electronic stopping power for Cobalt (Co) ions in Gallium Arsenide (GaAs) optoelectronic devices
No full textComparison Of Ridge Filters Performance in Human Vein Extraction Using 850nm Near Infrared Led Illumination
Get PDFVein pattern recognition has gained significant attention in recent years due to its potential applications in various fields such as biometrics, medical diagnosis, and security systems. The vein feature extraction algorithm is a crucial factor in the vein visualisation process. This paper investigates the performance of the ridge filters algorithm for vein feature extraction by using the NIR imaging technique to visualise human vein vessels. The 850nm NIR LED spectrum was employed as the vein illumination source combined with no infrared filter camera as the image sensor device. The reflective NIR imaging method was utilised in the experimental setup. Four prominent types of ridge filters, namely Hessian, Meijering, Sato and Frangi, were evaluated in detecting the human vein vessel. Through the evaluations of the comparisons, we demonstrate that Hessian filters offer superior performance in human vein detection for feature extraction using the near-infrared LED 850nm electromagnetic spectrum as the vein illumination source
Effects of high energy neutrons and resulting secondary charged particles on the operation of MOSFETs
No full textRadiation damage effects on zinc oxide (ZnO) based semiconductor devices– a review
Get PDFIn space, semiconductor devices are vulnerable to various effect of high energy radiation, causing single event upsets (SEUs), damaging or altering the lattice structure of the semiconductor device. The effect of ionizing radiation on metal oxide semiconductor device had been receiving very little attention as most research focus on polycrystalline silicon-based semiconductor. Based on our previous research studies specifically on gamma radiation exposure, the interaction effects of radiation towards ZnO based semiconductors shows changes across all 4 different types of parameter, namely the morphology, structural and optical as well as the electrical properties. As a general classification, morphological change is attributed to the interaction within the crystal lattice, while structural distortion is due to high energy displacement cascade, whereas changes in the optical properties relates to the formation of colour centres (F-centre). The overall parametric changes will then affect the electrical properties as degradation of general parameters will lead to the increase of the ideality factor of the ZnO semiconductor device. The increase of the ideality factor after irradiation is attributed to the production of recombination centres in the space charge region. Furthermore, large values of the ideality factor, obtained after irradiation, point out extrinsic recombination mechanisms where the initial and final states of recombination are located at a lattice imperfection such as a dangling bond or a complex involving impurity atoms and vacancies. Therefore, in this paper a more thorough review of past research on the radiation related studies on ZnO is discussed. This review aims to provide an in-depth discussion on various radiation effects of zinc oxide based semiconductor devices
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