Improvement in spontaneous emission rates for InGaN quantum wells on ternary InGaN substrate for light-emitting diodes

The spontaneous emission characteristics of green-and red-emitting InGaN quantum wells (QWs) on ternary InGaN substrate are analyzed, and the radiative recombination rates for the QWs grown on ternary substrate were compared with those of InGaN QWs on GaN templates. For green-and red-emitting InGaN QWs on In(0.15)Ga(0.85)N substrate, the spontaneous emission rates were found as similar to 2.5-3.2 times of the conventional approach. The enhancement in spontaneous emission rate can be achieved by employing higher In-content InGaN ternary substrate, which is also accompanied by a reduction in emission wavelength blue-shift from the carrier screening effect. The use of InGaN substrate is expected to result in the ability for growing InGaN QWs with enhanced spontaneous emission rates, as well as reduced compressive strain, applicable for green-and red-emitting light-emitting diodes. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3668117]