Progress in the optical studies of single InGaN/GaN quantum dots

Abstract

The great success that GaN-based structures have enjoyed in implementing efficient optoelectronic devices has fostered a rapidly expanding interest amongst researchers aimed at understanding their underlying physics. There has been an active debate on the mechanisms that give rise to efficient luminescence in these materials. In this paper we approach these questions through optical studies of single InGaN/GaN quantum dots in the context of the available experimental and theoretical understanding of InGaN structures in general, and of three-dimensional localization in this material in particular. We will also show how it is possible to exploit the various unique properties that nitride-based materials offer, such as the strong inbuilt electric field, in a controlled manner. Such control may in the future prove essential for the implementation of single quantum dot devices in applications such as quantum information processing. We also show how nonlinear spectroscopy provides an invaluable tool in suppressing background luminescence effects inherent in this material.

Acknowledgements

This research is part of the QIP IRC (www.qipirc.org) supported by EPSRC (GR/S82176/01). We also acknowledge funding from the Clarendon Fund and the ORS scheme (AFJ), and from Peterhouse, Cambridge (RAO).