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

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. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)