Article

Al0.83In0.17N lattice-matched to GaN used as an optical blocking layer in GaN-based edge emitting lasers

Ecole Polytechnique Fédérale de Lausanne (EPFL), Institute of Quantum Electronics and Photonics, CH-1015 Lausanne, Switzerland
Applied Physics Letters (Impact Factor: 3.52). 06/2009; 94(19):193506 - 193506-3. DOI: 10.1063/1.3138136
Source: IEEE Xplore

ABSTRACT Nitride-based blue laser diode structures with either Al 0.83 In 0.17 N / Al 0.07 Ga 0.93 N or Al 0.87 In 0.13 N bottom claddings have been fabricated and compared to standard structures including solely Al 0.07 Ga 0.93 N bottom claddings. Lasing emission at 415 nm is achieved in gain-guided structures at room temperature under pulsed current injection. Devices including the Al 0.83 In 0.17 N / Al 0.07 Ga 0.93 N bottom cladding exhibit superior device performance. This is a consequence of a better optical mode confinement, as expected from modeling.

0 Followers
 · 
89 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: The current transport properties of an n -doped, lattice matched AlInN layer with multiple, periodic GaN insertions are reported. Samples with three and seven insertions were grown and mesa structures were etched through the AlInN structures to different depths to determine the voltage contribution from each heterointerface. The quality of the AlInN surface improved with the GaN insertions and with reducing the thickness of the individual AlInN layers from 80 nm to 55 nm. Simulations suggest that the large conduction band discontinuity can lead to high turn on voltages which can be reduced by high levels of doping. Current-voltage measurements through the full structure show a diode characteristic which is temperature activated. A quasi-linear current-voltage characteristic is measured when the current is driven only through the uppermost GaN interlayer with 80 nm thick AlInN layers, indicating current leakage through defects in these layers (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
    physica status solidi (c) 07/2011; 8(7‐8). DOI:10.1002/pssc.201001165
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We demonstrate InGaN laser diodes with substantially reduced thickness of their bottom AlGaN cladding grown on plasmonic GaN substrate. The electron concentration in plasmonic substrate grown by ammonothermal method was of the order of 1020 cm−3, which corresponds to the refractive index reduction by 0.7% when comparing to undoped GaN. We were able to reduce the thickness of AlGaN bottom claddings from the initial 800 nm down to 400 nm without any worsening of laser threshold current or near-field patterns. The results are in agreement with the optical modeling of the InGaN laser diode structure fabricated on plasmonic GaN substrate.
    Applied Physics Letters 04/2013; 102(15). DOI:10.1063/1.4801949 · 3.52 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We investigate the thermal stability of nearly lattice-matched InAlN layers under metal organic vapor phase epitaxy conditions for temperatures >800 °C and show that they are not fully stable. In particular, InAlN top layers undergo degradation during high temperature annealing due to a surface related process, which causes the loss of crystal quality. This strongly impacts the transport properties of InAlN/GaN HEMT heterostructures; in particular, the mobility is significantly reduced. However, we demonstrate that high thermal stability can be achieved by capping with a GaN layer as thin as 0.5 nm. Those findings enabled us to realize in situ passivated HEMT heterostructures with state of the art transport properties.
    Applied Physics Letters 09/2014; 105(11):112101-112101-4. DOI:10.1063/1.4895807 · 3.52 Impact Factor