%0 Conference Paper
%F Oral 
%T Towards purely radiative recombination at room-temperature in nonpolar AlGaN/GaN quantum wells.
%+ Institute of Condensed Matter Physics [Lausanne]
%+ Cavendish Laboratory
%+ Institute of High Pressure Physics [Warsaw] (IHPP)
%+ Laboratoire Charles Coulomb (L2C)
%+ Ecole Polytechnique Fédérale de Lausanne (EPFL)
%A Corfdir, Pierre
%A Dussaigne, Amélie
%A Shahmohammadi, Mehran
%A Teisseyre, Henryk
%A Suski, Tadeusz
%A Grzegory, Izabella
%A Lefebvre, Pierre
%A Giraud, E.
%A Ganière, Jean-Daniel
%A Phillips, Richard T.
%A Grandjean, Nicolas
%A Deveaud, Benoit
%< avec comité de lecture
%B E-MRS Fall Meeting
%C Varsovie, Poland
%8 2013-09-16
%D 2013
%Z Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci]
%Z Physics [physics]/Physics [physics]/Optics [physics.optics]
%Z Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics
%Z Engineering Sciences [physics]/Optics / PhotonicConference papers
%X In contrast to GaN-based structures grown along [0001], nonpolar growth allows for the realization of thick quantum wells (QWs) with an optimal overlap between electron and hole wavefunctions. However, nonpolar GaN layers grown on non-lattice-matched substrates exhibit high densities of defects. Then, even at low temperature (T), the carrier recombination is mainly nonradiative.Here, we present the dynamics of charge carriers in AlGaN/GaN QWs of various widths and Al-contents grown on the a-facet of GaN crystals. The QW dislocation density and the exciton diffusion length at 300K are 2.105 cm-2 and 100 nm, respectively. Therefore, dislocations play a minor role in the carrier dynamics at 300K. For all samples, we observe an increasing QW PL lifetime with T, indicating the absence of nonradiative phenomena in the low-T range. Purely radiative recombination is observed up to 240K for a 7 nm thick QW. This suggests the possibility of realizing UV emitters with narrow emission and high internal quantum efficiency at 300K.The observed decrease in QW PL lifetime in the high-T range arises from the thermal escape of carriers from the QW to the AlGaN barriers and their subsequent nonradiative recombination. The efficiency of nonradiative recombination at 300K is thus reduced by limiting the thermal escape of carriers from the QW. This is obtained by growing thick QWs rather than increasing the barrier Al-content, which is important from point of view of defect generation.
%G English
%L hal-01907907
%U https://hal.science/hal-01907907
%~ CNRS
%~ L2C
%~ MIPS
%~ UNIV-MONTPELLIER
%~ UM-2015-2021