Efficient radiative recombination from «112̄2» -oriented InxGa1-xN multiple quantum wells fabricated by the regrowth technique

Abstract

InxGa1-xN multiple quantum wells (QWs) with [0001], «112̄2», and «112̄0» orientations have been fabricated by means of the regrowth technique on patterned GaN template with striped geometry, normal planes of which are (0001) and {112̄0}, on sapphire substrates. It was found that photoluminescence intensity of the {112̄2} QW is the strongest among the three QWs, and the internal quantum efficiency of the {112̄2} QW was estimated to be as large as about 40% at room temperature. The radiative recombination lifetime of the {112̄2} QW was about 0.38 ns at low temperature, which was 3.8 times shorter than that of conventional [0001]-oriented InxGa1-xN QWs emitting at a similar wavelength of about 400 nm. These findings strongly suggest the achievement of stronger oscillator strength owing to the suppression of piezoelectric fields. © 2004 American Institute of Physics.