Publications related to Blue laser

Study of growth-induced point defects and their impact on InGaN-based optoelectronic devices

GaN exhibits a decomposition tendency for temperatures far below its melting point and common growth temperatures used in metal-organic vapour phase epitaxy (MOVPE).This characteristic is known to be a major obstacle for realising GaN bulk substrate. There ...

EPFL2024

III-N blue-emitting epi-structures with high densities of dislocations: Fundamental mechanisms for efficiency improvement and applications

Pierre Christophe Lottigier

Since the dawn of humanity, human beings seeked to light their surroundings for their well-being, security and development. The efficiency of ancient lighting devices, e.g. oil lamps or candles, was in the order of 0.03-0.04% and jumped to 0.4-0.6% with th ...

EPFL2024

Persistent enhancement of exciton diffusivity in CsPbBr3 nanocrystal solids

Seryio Saris

In semiconductors, exciton or charge carrier diffusivity is typically described as an inherent material property. Here, we show that the transport of excitons among CsPbBr3 perovskite nanocrystals (NCs) depends markedly on how recently those NCs were occup ...

Amer Assoc Advancement Science2024

Polariton lasing in AlGaN microring with GaN/AlGaN quantum wells

Nicolas Grandjean, Jean-François Carlin, Raphaël Butté

Microcavity polaritons are strongly interacting hybrid light-matter quasiparticles, which are promising for the development of novel light sources and active photonic devices. Here, we report polariton lasing in the UV spectral range in microring resonator ...

AIP Publishing2023

The nanoscale impact of individual nonradiative point defects on InGaN/GaN quantum wells

Thomas Fjord Kjaersgaard Weatherley

Today's world depends on optoelectronic devices: light-emitting diodes illuminate our houses and backlight the displays on our gadgets, while laser diodes underpin fibre-optic communication. Such optoelectronic devices rely on crystalline semiconductor het ...

EPFL2023

Single-frequency violet and blue laser emission from AlGaInN photonic integrated circuit chips

Tobias Kippenberg, Anat Siddharth

Chip-based, single-frequency and low phase-noise integrated photonic laser diodes emitting in the violet (412 nm) and blue (461 nm) regime are demonstrated. The GaN-based edge-emitting laser diodes were coupled to high-quality on-chip micro-resonators for ...

Optica Publishing Group2023

X-ray qualification of hydrogenated amorphous silicon sensors on flexible substrate

Sylvain Dunand, Mikaël Martino, Nicolas Würsch, Luca Massimiliano Antognini, Matthew James Large

Hydrogenated amorphous silicon (a-Si:H) is a well known material for its radiation resistance and for the possibility of deposition on flexible substrates like Polyimide (PI), polyethylene terephthalate (PET) or polyethylene naphthalate (PEN). Due to the p ...

IEEE2023

Ultrafast tunable lasers using lithium niobate integrated photonics

Tobias Kippenberg, Rui Ning Wang, Anat Siddharth, Mikhail Churaev, Viacheslav Snigirev, Junqiu Liu, Guanhao Huang

Early works(1) and recent advances in thin-film lithium niobate (LiNbO3) on insulator have enabled low-loss photonic integrated circuits(2,3), modulators with improved half-wave voltage(4,5), electro-optic frequency combs(6) and on-chip electro-optic devic ...

NATURE PORTFOLIO2023

Modeling the electrical characteristic of InGaN/GaN blue-violet LED structure under electrical stress

Nicolas Grandjean, Jean-François Carlin, Camille Haller

The role of deep defects and their physical origin in InGaN/GaN LED are still widely investigated and debated, in particular their impact on the electrical and optical characteristics and on the reliability of the device. In this paper we evaluate the elec ...

PERGAMON-ELSEVIER SCIENCE LTD2022

On the Response Speed of Narrowband Organic Optical Upconversion Devices

Frank Nüesch, Roland Hany, Surendra Babu Anantharaman, Matthias Diethelm, Wei-Hsu Hu

Organic upconversion devices (OUCs) consist of an organic infrared photodetector and an organic visible light-emitting diode (OLED), connected in series. OUCs convert photons from the infrared to the visible and are of use in applications such as process c ...

WILEY-V C H VERLAG GMBH2022

Deep defects in InGaN LEDs: modeling the impact on the electrical characteristics

Nicolas Grandjean, Jean-François Carlin, Camille Haller

Deep defects have a fundamental role in determining the electro-optical characteristics and in the efficiency of InGaN light-emitting diodes (LEDs). However, modeling their effect on the electrical characteristics of the LED is not straightforward. ...

SPIE-INT SOC OPTICAL ENGINEERING2022

Thermal Modelling and Experimental Validation in the Perspective of Tool Steel Laser Polishing

Eric Boillat, Alexandre Masserey, Bastian Meylan

Laser polishing (LP) is a process that allows a significant reduction of the surface roughness of a metal workpiece via re-melting a shallow layer of material. However, the practical use of LP is limited due to the difficulty of satisfying the high surface ...

MDPI2022

A Generalized Phase-Shift PWM Extension for Improved Natural and Active Balancing of Flying Capacitor Multilevel Inverters

Elison de Nazareth Matioli, Georgios Kampitsis

The emergence of wide bandgap power devices has brought the attention back to the flying capacitor (FC) multilevel inverters with a large number of stages, in an effort to increase the power density by minimizing the passive components. The main challenge ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2022

Effects of quantum-well indium content on deep defects and reliability of InGaN/GaN light-emitting diodes with under layer

Nicolas Grandjean, Jean-François Carlin, Camille Haller

We investigate the density of defects and the degradation rate in InGaN light-emitting diodes having identical dislocation density and epitaxial structure, but different indium content in the quantum well (QW; 12%, 16%, 20%). Our results, based on combined ...

IOP PUBLISHING LTD2021

Modeling the electrical characteristics of InGaN/GaN LED structures based on experimentally-measured defect characteristics

Nicolas Grandjean, Jean-François Carlin, Camille Haller

Defects can significantly modify the electro-optical characteristics of InGaN light-emitting diodes (LEDs); however, modeling the impact of defects on the electrical characteristics of LEDs is not straightforward. In this paper, we present an extensive inv ...

IOP PUBLISHING LTD2021

Defect incorporation in In-containing layers and quantum wells: experimental analysis via deep level profiling and optical spectroscopy

Nicolas Grandjean, Jean-François Carlin, Mauro Mosca, Camille Haller

Recent studies demonstrated that the performance of InGaN/GaN quantum well (QW) light emitting diodes (LEDs) can be significantly improved through the insertion of an InGaN underlayer (UL). The current working hypothesis is that the presence of the UL redu ...

IOP PUBLISHING LTD2021

p-NiO Junction Termination Extensions for High Voltage Vertical GaN Devices

Elison de Nazareth Matioli, Remco Franciscus Peter van Erp, Luca Nela, Riyaz Mohammed Abdul Khadar, Catherine Erine, Taifang Wang, Alessandro Floriduz, Pirouz Sohi, Reza Soleiman Zadeh Ardebili

In this paper, we illustrate the use of RF-sputtered p-NiO to fabricate Junction Termination Extensions (JTEs) for high-performance vertical GaN-on-Si Schottky Barrier Diodes (SBDs). The GaN epitaxial structures were grown on 6-inch Si wafers by MOCVD. The ...

IEEE2021

High-Performance Enhancement-Mode AlGaN/GaN Multi-Channel Power Transistors

Elison de Nazareth Matioli, Remco Franciscus Peter van Erp, Halil Kerim Yildirim, Jun Ma, Luca Nela, Catherine Erine

AlGaN/GaN devices have shown outstanding potential for power conversion applications. However, despite the recent progress, their performance is still far from what the material can offer in terms of on-resistance and breakdown voltage. To address this cha ...

IEEE2021

GaN vertical power devices on silicon substrates

Riyaz Mohammed Abdul Khadar

Gallium Nitride (GaN) is a wonder material which has widely transformed the world by enabling energy-efficient white light-emitting diodes. Over the past decade, GaN has also emerged as one of the most promising materials for developing power devices which ...

EPFL2021

Heterostructure design and field management in III-N high-electron mobility electronic devices

Catherine Erine

III-N family of materials has offered multiple groundbreaking technologies in the field of optoelectronics and high-power radio-frequency (RF) devices. Blue light-emitting diodes (LEDs) have revolutionized low-energy lighting. Gallium nitride (GaN) RF mark ...

EPFL2021