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View article: Diffusion mechanism as cause of optical degradation in AlGaN-based UV-C leds investigated by TCAD simulations
Diffusion mechanism as cause of optical degradation in AlGaN-based UV-C leds investigated by TCAD simulations Open
We investigate the degradation physics of AlGaN-based UV-C LEDs emitting at 265 nm, by combined experimental measurements and numerical simulations. We demonstrate that: (i) during long-term operation, devices show degradation in the optic…
View article: Efficiency- and lifetime-limiting effects of commercially available UVC LEDs: a review
Efficiency- and lifetime-limiting effects of commercially available UVC LEDs: a review Open
This review is aimed at providing an overview of the technologies of currently-available UVC LEDs, on the challenges that these devices have to face, and on the peculiar features that these modern solid-state emitters exhibit. In particula…
View article: Systematic analysis of the trapping and reliability of Al2O3/GaN MOS capacitors with different atomic layer deposition techniques
Systematic analysis of the trapping and reliability of Al2O3/GaN MOS capacitors with different atomic layer deposition techniques Open
We investigate the robustness and charge trapping phenomena under positive and negative bias stress in Al2O3/n-GaN metal-oxide-semiconductor capacitors fabricated with different atomic layer deposition (ALD) techniques: (i) thermal ALD (Th…
View article: Modeling the capacitance–voltage characteristics of AlGaN-based UV-C LEDs
Modeling the capacitance–voltage characteristics of AlGaN-based UV-C LEDs Open
We propose a detailed approach for modeling the C-V characteristic of complex heterostructure-based devices, investigating the case of UV-C LEDs. The study is based on combined experimental measurements and TCAD simulations, and explores: …
View article: Long-term (8000 h) reliability and failures of high-power LEDs for outdoor lighting stressed at high ambient temperatures
Long-term (8000 h) reliability and failures of high-power LEDs for outdoor lighting stressed at high ambient temperatures Open
View article: Changes in the extraction and collection efficiency of GaN-based MQW solar cells under optical step-stress
Changes in the extraction and collection efficiency of GaN-based MQW solar cells under optical step-stress Open
View article: Investigating the optical degradation of InAs quantum dot lasers on silicon through combined electro-optical characterization and gain measurements
Investigating the optical degradation of InAs quantum dot lasers on silicon through combined electro-optical characterization and gain measurements Open
We evaluate the degradation of 1.3 µ m InAs quantum-dot laser diodes epitaxially grown on silicon. For the first time, the optical degradation mechanisms are investigated by evaluating the variations in the gain spectra measured during a c…
View article: Long-Term Analysis of Temperature and Current-Dependent Degradation in Green High-Power Light-Emitting Diodes
Long-Term Analysis of Temperature and Current-Dependent Degradation in Green High-Power Light-Emitting Diodes Open
We report on the degradation dynamics and mechanisms of commercially available green high-power light-emitting diodes (LEDs) with a peak wavelength of 522 nm. The stress tests were carried out for up to 8800 hours with forward currents ran…
View article: Vertical GaN Devices: Reliability Challenges and Lessons Learned from Si and SiC
Vertical GaN Devices: Reliability Challenges and Lessons Learned from Si and SiC Open
International audience
View article: Effect of High Monochromatic Radiation on the Electrical Performance of CIGS Solar Cell
Effect of High Monochromatic Radiation on the Electrical Performance of CIGS Solar Cell Open
In this article, we investigate the optically induced degradation of Cu(InGa)Se2 (CIGS) solar cells subjected to monochromatic laser irradiation. The devices under test are bifacial CIGS solar cells, fabricated on fluorine-doped SnO2 glass…
View article: Quality Assessment of Perovskite Solar Cells: An Industrial Point of View
Quality Assessment of Perovskite Solar Cells: An Industrial Point of View Open
The mass production of photovoltaic (PV) devices requires fast and reliable characterization methods and equipment. PV manufacturers produce a complete module roughly every 20 s, and the electrical performance assessment is typically compl…
View article: Investigation and modeling of the role of interface defects in the optical degradation of InGaN/GaN LEDs
Investigation and modeling of the role of interface defects in the optical degradation of InGaN/GaN LEDs Open
We investigate the degradation mechanisms of In 0.2 Ga 0.8 N/GaN light emitting diodes through combined experimental analysis and simulations. The devices were submitted to constant current stress at 100 mA. Depending on the measuring curr…
View article: Degradation of 1.3 μm Quantum Dot Laser Diodes for Silicon Photonics: Dependence on the Number of Dot-in-a-Well Layers
Degradation of 1.3 μm Quantum Dot Laser Diodes for Silicon Photonics: Dependence on the Number of Dot-in-a-Well Layers Open
For the first time, we analyze the optical degradation of 1.3 mm InAs quantum dot laser diodes (QD LDs) epitaxially grown on silicon as a function of the number of dot-in-a-well layers (DWELLs). To this aim, we tested the reliability of tw…
View article: Advanced defect spectroscopy in wide-bandgap semiconductors: review and recent results
Advanced defect spectroscopy in wide-bandgap semiconductors: review and recent results Open
The study of deep-level defects in semiconductors has always played a strategic role in the development of electronic and optoelectronic devices. Deep levels have a strong impact on many of the device properties, including efficiency, stab…
View article: Impact of the Oxide Aperture Width on the Degradation of 845 Nm VCSELs for Silicon Photonics
Impact of the Oxide Aperture Width on the Degradation of 845 Nm VCSELs for Silicon Photonics Open
For the first time, we analyzed the degradation as a function of the oxide aperture in 845 nm VCSELs designed for silicon photonics (SiPh) applications. First, we evaluated the optical degradation of the devices by collecting EL images dur…
View article: Investigation of degradation dynamics of 265 nm LEDs assisted by EL measurements and numerical simulations
Investigation of degradation dynamics of 265 nm LEDs assisted by EL measurements and numerical simulations Open
We studied four AlGaN-based 265 nm LEDs with increasing QW thickness (1.4, 3, 6 and 9 nm) during a constant current stress at 100 A cm −2 . We focused our attention on the parasitic components of the emission spectra at low current levels …
View article: Fast Characterization of Power LEDs: Circuit Design and Experimental Results
Fast Characterization of Power LEDs: Circuit Design and Experimental Results Open
A precise measurement of optical power, forward voltage, and junction temperature of light-emitting diodes (LEDs) is the key for characterization and health monitoring of these devices. In many cases, LED characterization is carried out wi…
View article: TCAD Modeling and Simulation of Dark Current-Voltage Characteristics in High-Periodicity InGaN/GaN Multiple-Quantum-Wells (MQWs) Solar Cells
TCAD Modeling and Simulation of Dark Current-Voltage Characteristics in High-Periodicity InGaN/GaN Multiple-Quantum-Wells (MQWs) Solar Cells Open
Gallium nitride (GaN) based high periodicity indium/GaN multiple quantum wells solar cells have recently been proposed for different applications: from operation in harsh environments, like space applications, to their use in concentrator …
View article: Robustness and reliability of high-power white LEDs under high-temperature, high-current stress
Robustness and reliability of high-power white LEDs under high-temperature, high-current stress Open
High-power white LEDs for outdoor lighting were submitted to accelerated lifetime stresses to evaluate their robustness and reliability. LEDs featured a 2 mm2 chip with 2 A absolute maximum current (Iabs) at 135 °C junction temperature. A …
View article: Guest Editorial: Special Issue on Wide and Ultrawide Band Gap Semiconductor Devices for RF and Power Applications
Guest Editorial: Special Issue on Wide and Ultrawide Band Gap Semiconductor Devices for RF and Power Applications Open
On behalf of myself and the other guest editors for the Special Issue on "Wide and Ultrawide Band Gap Semiconductor Devices for RF and Power Applications" featured in this month's IEEE Transactions on Electron Devices, we are pleased to of…
View article: V-Pits and Trench-Like Defects in High Periodicity MQWs GaN-Based Solar Cells: Extensive Electro-Optical Analysis
V-Pits and Trench-Like Defects in High Periodicity MQWs GaN-Based Solar Cells: Extensive Electro-Optical Analysis Open
By combining microscopy investigation, light-beam induced current (LBIC), micro-photoluminescence ( mu -PL), and micro-electroluminescence ( mu -EL) characterization, we investigate the electrical and optical properties of V-pits and trenc…
View article: Modeling of the Electrical Characteristics and Degradation Mechanisms of UV-C LEDs
Modeling of the Electrical Characteristics and Degradation Mechanisms of UV-C LEDs Open
In this paper we investigate the reliability of AlGaN-based UV-C LEDs with an emission wavelength of 265 nm. By submitting the devices to constant current stress, two main electrical degradation processes are identified: a turn-on voltage …
View article: Review and Outlook on GaN and SiC Power Devices: Industrial State-of-the-Art, Applications, and Perspectives
Review and Outlook on GaN and SiC Power Devices: Industrial State-of-the-Art, Applications, and Perspectives Open
We present a comprehensive review and outlook of silicon carbide (SiC) and gallium nitride (GaN) transistors available on the market for current and next-generation power electronics. Material properties and structural differences among Ga…
View article: Modeling the Electrical Degradation of Micro-transfer-Printed 845 nm VCSILs for Silicon Photonics
Modeling the Electrical Degradation of Micro-transfer-Printed 845 nm VCSILs for Silicon Photonics Open
This article deals for the first time with the electrical degradation of novel 845 nm vertical-cavity silicon-integrated lasers (VCSILs) for silicon photonics (SiPh). We analyzed the reliability of these devices by submitting them to high …
View article: Negative Activation Energy of Gate Reliability in Schottky-Gate p-GaN HEMTs: Combined Gate Leakage Current Modeling and Spectral Electroluminescence Investigation
Negative Activation Energy of Gate Reliability in Schottky-Gate p-GaN HEMTs: Combined Gate Leakage Current Modeling and Spectral Electroluminescence Investigation Open
For the first time, we use electrical characterization, spectrally-resolved electroluminescence measurements and degradation tests to explain the negative activation energy of gate reliability in power GaN HEMTs with p-GaN Schottky gate. F…
View article: Addressing the Optical Degradation of 1.3 μm Quantum Dot Lasers through Subthreshold Characterization
Addressing the Optical Degradation of 1.3 μm Quantum Dot Lasers through Subthreshold Characterization Open
We propose a novel methodology capable of separately evaluating the contribution of the different recombination processes in quantum dot laser diodes (QD LDs) driven below-threshold. The proposed approach is based on the analysis of the su…
View article: Microwave and Millimeter-Wave GaN HEMTs: Impact of Epitaxial Structure on Short-Channel Effects, Electron Trapping, and Reliability
Microwave and Millimeter-Wave GaN HEMTs: Impact of Epitaxial Structure on Short-Channel Effects, Electron Trapping, and Reliability Open
Application of gallium nitride high-electron-mobility transistors (GaN HEMTs) to millimeter-wave power amplifiers requires gate length scaling below 150 nm: in order to control short-channel effects, the gate-to-channel distance must be de…
View article: Impact of high-temperature operating lifetime tests on the stability of 0.15 μm AlGaN/GaN HEMTs: A temperature-dependent analysis
Impact of high-temperature operating lifetime tests on the stability of 0.15 μm AlGaN/GaN HEMTs: A temperature-dependent analysis Open
View article: Early failure of high-power white LEDs for outdoor applications under extreme electrical stress: Role of silicone encapsulant
Early failure of high-power white LEDs for outdoor applications under extreme electrical stress: Role of silicone encapsulant Open
View article: Influence of V-Pits on the Turn-On Voltage of GaN-Based High Periodicity Multiple Quantum Well Solar Cells
Influence of V-Pits on the Turn-On Voltage of GaN-Based High Periodicity Multiple Quantum Well Solar Cells Open
Based on combined electrical analysis, microscopy investigation, and two-dimensional simulations we investigate the influence of V-pits on the turn-on voltage and current-voltage characteristics of high periodicity InGaN-GaN multiple quant…