Publications de Nils Asmus Kristian Kaufmann

Critical impact of Ehrlich-Schwobel barrier on GaN surface morphology during homoepitaxial growth

Nicolas Grandjean, Denis Martin, Lise Lahourcade, Nils Asmus Kristian Kaufmann

We discuss the impact of kinetics, and in particular the effect of the Ehrlich-Schwobel barrier (ESB), on the growth and surface morphology of homoepitaxial GaN layers. The presence of an ESB can lead to various self-assembled surface features, which stron ...

Elsevier Science Bv2016

Investigation of indium-rich InGaN alloys and kinetic growth regime of GaN

Nils Asmus Kristian Kaufmann

Nowadays, light emitting diodes (LEDs) and laser diodes (LDs) are part of our daily life. More and more devices incorporate InGaN-based optoelectronic devices. In fact, since the first demonstration of a candela-class InGaN-based LED in the beginning of th ...

EPFL2013

Thermal annealing of molecular beam epitaxy-grown InGaN/GaN single quantum well

Nicolas Grandjean, Denis Martin, Nils Asmus Kristian Kaufmann

The effect of thermal annealing on In0.25Ga0.75N/GaN quantum wells grown by molecular beam epitaxy at 550 degrees C is investigated. A strong increase in the 300 K photoluminescence (PL) intensity is observed for samples annealed at 880 degrees C, while de ...

Iop Publishing Ltd2012

Strain compensation in AlInN/GaN multilayers on GaN substrates: Application to the realization of defect-free Bragg reflectors

Nicolas Grandjean, Jean-François Carlin, Raphaël Butté, Gatien Cosendey, Nils Asmus Kristian Kaufmann

We report on the growth conditions of AlInN layers grown on free-standing GaN substrates. We found that an average indium content of similar to 20% is needed to obtain defect-free AlInN/GaN multilayers. This is larger than the commonly accepted value of 18 ...

AIP American Institute of Physics2011

Investigation of the In composition in InGaN/GaN quantum wells deposited by MOVPE and/or MBE with emission from violet to green

Nicolas Grandjean, Denis Martin, Nils Asmus Kristian Kaufmann

Transmission electron microscopy and photoluminescence investigations have been carried out on a series of quantum wells grown by molecular beam epitaxy and metal organic vapour phase epitaxy. In both cases, the emission wavelength and the peak width agree ...

2011