Optical Studies of Non-linear Absorption in Single InGaN/GaN Quantum Dots.

Micro-photoluminescence properties of single InGaN/GaN quantum dots (QDs) are investigated using sub-bandgap excitation by 1 ps pulses from a Ti:sapphire laser. This results in almost complete suppression of background emission arising from the underlying quantum well to which the QDs are coupled. Photoluminescence excitation spectra undertaken using this technique show evidence of p-states. The non-linear intensity dependence of the emission is also discussed. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]