Strain-induced piezoelectric field effects on light emission energy and intensity from AlInGaN/InGaN quantum wells

We report on the effects of the piezoelectric field and well width on the t ransition energy and intensity for InGaN quantum well structures with GaN o r AlInGaN quaternary barriers. It was found that the emission energy of com pressively strained GaN/In0.08Ga0.92N quantum wells exhibits a strong well width dependence not accounted for by quantum confinement subband energy sh ifting alone. However, for unstrained quantum well layers with quaternary b arriers, no emission energy dependence on width was observed due to the eli mination of the piezoelectric field, which was measured to be at least 0.6 MV/cm for the strained quantum wells. Furthermore, the unstrained quantum w ells demonstrated a higher intensity than their strained counterparts for a ll quantum well widths investigated. The current data will help clarify the origin of emission in InGaN quantum wells. (C) 2001 American Institute of Physics.