Abstract. Triangular-shaped InGaN/GaN multiple quantum wells (MQWs) grown on a sapphire substrate were adopted as an active layer of light-emitting diodes (LEDs). The temperature dependence of the normalized integrated photoluminescence (PL) intensity showed that the internal quantum efficiency (IQE) of the LEDs with triangular-shaped MQW is much higher than that of the LEDs with conventional rectangular MQW structures. The electroluminescence (EL) spectra of the two series devices have been comparatively studied as functions of injection current. It was found that the device with the triangular-shaped MQW structure exhibited a stronger intensity and a narrower linewidth. Furthermore, the peak energy is nearly independent of the injection current, indicating that the triangular MQW LEDs are more efficient and stable than the rectangular ones.

Print publication: Issue 12 (December 2009)
Received 8 July 2009, in final form 30 September 2009
Published 3 November 2009