Semipolar InGaN/GaN nanostructure light-emitting diodes on c-plane sapphire

Abstract

The fabricati on of electr ically in jected trian gular-nan ostripe core- shell semipolar III- nitride LEDs (TLEDs) is demon strated using inte rferometr ic lithogr aphy and catalyst-fr ee bottom-up sel ective-area met al- organic chemica l vapo r deposition (MO CVD). This al ternative approa ch enab les semipolar orie ntations on inexpe nsive, c-plane sapphire substrates, in comparison with planar growth on free-standing GaN substrates. Transmission electron microscopy and energy dispersive X-ray spectroscopy reveal nonuniform quantum well thickness and composition, respectively, as a function of location on the triangular stripes. The broad electroluminescence spectra, wavelength shift with increasing current density, and nonlinear light vs current characteristics are well correlated with the observed quantum-well nonuniformities.