The main optical properties of III-nitride (III-N) heterostructures will be reviewed. We shall first define spontaneous and piezoelectric polarizations which are inherent to III-N semiconductors crystallizing with the wurtzite phase [1]. It will be shown that polarization discontinuities are responsible for the built-in electric field present in III-N heterostructures grown along the c-axis [2]. The physics will be illustrated by considering low Al content GaN/AlGaN quantum wells (QWs) [3], which exhibit a quality allowing probing their intrinsic properties. In particular, we shall describe the experimental signature of the quantum confined Stark effect (QCSE) [4] and the subsequent decrease of the radiative efficiency of QWs with increasing well thickness. The observation of well-resolved A and B excitonic resonances in the reflectivity spectra of high quality GaN QWs [5] and the biexcitonic properties of the latter [6] will be treated. The possible origins explaining the high quantum efficiency of In-based III-N QWs, which are presently at the heart of the huge success of UV-blue III-N optoelectronic devices, will also be discussed [7]. Finally, the concept of non- and semi-polar QWs, where the QCSE is either suppressed or decreased, for the realization of more efficient light-emitters will be introduced [8].

[1] F. Bernardini, V. Fiorentini, and D. Vanderbilt, Phys. Rev. B 56, R10024 (1997)

[2] See, e.g., R. Butté and N. Grandjean, in Polarization Effects in Semiconductors, ed. by C. Wood and D. Jena (Springer, New York, 2008)

[3] E. Feltin et al., Appl. Phys. Lett. 90, 021905 (2007)

[4] M. Leroux et al., Phys. Rev. B 58, R13371 (1998)

[5] F. Stokker-Cheregi et al., Phys. Rev. B 79, 245316 (2009)

[6] F. Stokker-Cheregi et al., Phys. Rev. B 77, 125342 (2008); ibid., Appl. Phys. Lett. 93, 152105 (2008)

[7] See, e.g., S. Nakamura, Science 281, 956 (1998); S. Pimputkar et al., , Nature. Photon. 3, 180 (2009)

[8] P. Waltereit et al., Nature (London) 406, 865 (2000)

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/21061 must be provided.

1. Room temperature polariton lasing and condensation effects in III-nitride microcavities