A5023295218- GaN-based semiconductor devices and materials
- Semiconductor Quantum Structures and Devices
- Semiconductor materials and devices
- Semiconductor Lasers and Optical Devices
- Photonic and Optical Devices
- ZnO doping and properties
- Thin-Film Transistor Technologies
- Ga2O3 and related materials
- Semiconductor materials and interfaces
- Nanowire Synthesis and Applications
- Silicon Carbide Semiconductor Technologies
- Advancements in Semiconductor Devices and Circuit Design
- Luminescence Properties of Advanced Materials
- Infection Control and Ventilation
- Impact of Light on Environment and Health
- Spectroscopy and Laser Applications
- Perovskite Materials and Applications
- Quantum Dots Synthesis And Properties
- Chalcogenide Semiconductor Thin Films
- Electronic and Structural Properties of Oxides
- Color Science and Applications
- Integrated Circuits and Semiconductor Failure Analysis
- Engineering Applied Research
- Organic Light-Emitting Diodes Research
- Silicon and Solar Cell Technologies
University of Padua
2016-2025
National Institute of Information and Communications Technology
2021
Over the last decade, gallium nitride (GaN) has emerged as an excellent material for fabrication of power devices. Among semiconductors which devices are already available in market, GaN widest energy gap, largest critical field, and highest saturation velocity, thus representing high-speed/high-voltage components. The presence spontaneous piezoelectric polarization allows us to create a two-dimensional electron gas, with high mobility large channel density, absence any doping, thanks use...
We present a comprehensive review and outlook of silicon carbide (SiC) gallium nitride (GaN) transistors available on the market for current next-generation power electronics. Material properties structural differences among GaN SiC devices are first discussed. Based analysis different commercially transistors, we describe state-of-the-art these technologies, highlighting preferential conversion topologies key characteristics each technological platform. Current future fields application...
Herein, the main factors and mechanisms that limit reliability of gallium nitride (GaN)‐based light‐emitting diodes (LEDs) are reviewed. An overview defects characterization techniques most relevant for wide‐bandgap is provided first. Then, by introducing a catalogue traps deep levels in GaN computer‐aided simulations, it shown which types more detrimental radiative efficiency devices. Gradual degradation analyzed terms their specific driving force: separate analysis recombination‐enhanced...
The long-term stability of ultraviolet (UV)-C light-emitting diodes (LEDs) is major importance for many applications. To improve the understanding in this field, we analyzed degradation AlGaN-based UVC LEDs and modeled variation electrical characteristics by 2D simulations based on results deep-level optical spectroscopy (DLOS). increase forward leakage current observed during ageing was ascribed an trap-assisted tunneling. analysis kinetics suggests role a defect diffusion process, possibly...
In this paper we investigate the reliability of AlGaN-based UV-C LEDs with an emission wavelength 265 nm. By submitting devices to constant current stress, two main electrical degradation processes are identified: a turn-on voltage shift and increase in forward leakage current. particular, these were respectively attributed to: (i) partial passivation Mg-doping concentration region adjacent contact, probably caused by local hydrogen diffusion, ii) diffusion/generation process defects...
This paper presents an extensive analysis of the operating principles, theoretical background, advantages and limitations laser-based lighting systems. In first part we discuss main issues lighting, present a comparison with conventional LED-lighting technology. second paper, original experimental data on stability reliability phosphor layers for laser based high light-intensity high-temperature degradation tests. third (for time) detailed between three different solutions (i) transmissive...
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiologic agent of COVID-19, which has affected international healthcare systems since beginning 2020. Among sanitizing approaches, UV irradiation a well-known technology often used in different environments to reduce microbial contamination and viral transmission. In particular, several works have demonstrated that UVC radiation able inactivate SARS-CoV-2 compromising its genome virion integrity. With this work we review...
With this study, we report on the reliability of most recent commercial UVC LED devices. The current COVID-19 pandemic urged development antiviral technologies, and one effective is based irradiation, which can be effectively achieved by means Deep UV LEDs. systems LEDs strongly depends their efficacy reliability. We propose an in-depth analysis four different state-of-the-art suitable for disinfection applications. have been subjected to a controlled stress test near application limits,...
Application of gallium nitride high-electron-mobility transistors (GaN HEMTs) to millimeter-wave power amplifiers requires gate length scaling below 150 nm: in order control short-channel effects, the gate-to-channel distance must be decreased, and device epitaxial structure has completely redesigned. A high 2-D electron gas (2DEG) carrier density can preserved even with a very thin top barrier layer by substituting AlGaN AlN, InAl(Ga)N, or ScAlN. Moreover, prevent interaction hot electrons...
Abstract The study of deep-level defects in semiconductors has always played a strategic role the development electronic and optoelectronic devices. Deep levels have strong impact on many device properties, including efficiency, stability, reliability, because they can drive several physical processes. Despite advancements crystal growth, wide- ultrawide-bandgap (such as gallium nitride oxide) are still strongly affected by formation that, general, act carrier traps or...
Abstract We evaluate the degradation of 1.3 µm InAs quantum-dot laser diodes epitaxially grown on silicon. For first time, optical mechanisms are investigated by evaluating variations in gain spectra measured during a constant-current stress test. Remarkably, showed that reduction peak modal is dominant compared to increse internal absorption losses. Moreover, increase threshold current (Ith) induced was found be correlated reduction. This experimental evidence modeling variation through...
We report on the design, characterization and validation of a spherical irradiation system for inactivating SARS-CoV-2, based UV-C 275 nm LEDs. The is designed to maximize intensity uniformity can be used irradiating volume 18 L. To this aim: (i) several commercially available LEDs have been acquired analyzed; (ii) complete optical study has carried out in order optimize efficacy system; (iii) resulting prototype characterized optically tested inactivation SARS-CoV-2 different exposure...
We investigate the impact of Mg-doping on performance and degradation kinetics AlGaN-based UV-C light-emitting diodes (LEDs). By comparing LEDs from three wafers with different nominal doping levels [Mg/(Al+Ga) ratio: 0.15%, 0.5%, 1% in gas phase during epitaxy] AlGaN:Mg electron-blocking layer (EBL), we demonstrate following results: (i) A higher EBL results a optical power at low current levels, which is ascribed to an increased hole injection efficiency. (ii) The reduction follows...