Two-step growth of InGaN quantum dots and application to light emitters

Abstract

A two-step growth method for creating InGaN quantum dots (QDs) was developed by using a combination of an InxGa1–xN nucleation layer (NL) without island structures and an InyGa1–yN formation layer (FL) with an indium content lower than that of the InxGa1–xN NL. The realization of QDs was confirmed by micro-photoluminescence (μ-PL) measurements only for the sample with both the InxGa1–xN NL and the InyGa1–yN FL. The spectral position of the QD ensemble recombination was controlled mainly by the deposition time of the InxGa1–xN NL. Green (∼520 nm) and amber (∼600 nm) LEDs with the QD layers grown by the two-step growth method as the active region were also fabricated and compared with that having InGaN QW layers, reported previously. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)