Low temperature spectral cathodoluminesceuce study of InGaAs/InP quantum dot like and quantum wire like structures

InGaAs/InP based quantum dot-like (QDLS) and quantum wire-like (QWRLS) structures grown respectively on square and on strip patterns on exact (100) and on 2 degrees off-axis InP substrates were studied using low temperature (T=5K) spectral cathodoluminescence (CL) in a scanning electron microscope (SEM). QDLS having the same size were observed to have significantly different CL emission band-shapes and band-peak positions. CL spectra of 0.8 mu m sized single QDLS, acquired using the spot mode of the SEM, showed that this variation was similar to 200 nm. Spot-mode CL spectra of 0.6 mu m wide single QWRLS showed a variation of the CL band-peak position along the wire length of similar to 350 nm. Large area monochromatic CL images taken at different wavelengths were used to map the CL spatial distribution in arrays of QDLS and QWRLS.