Structural and optical properties of InGaAs ridge quantum wire Arrays with sub-micron pitches grown by selective MBE on InP substrates

A systematic microstructural and optical characterization has been carried out on linear arrays of InAlAs/InGaAs/InAlAs ridge quantum wires (QWRs) grown by selective MBE on patterned InP (001) substrates, by scanning electron microscopy (SEM), cross-sectional transmission microscopy (TEM), atomic force microscopy (AFM), and cathodoluminescence (CL) and photoluminescence (PL) techniques. The microstructural analysis proved high integrity and high uniformity of the top ridge region of the QWRs. It also showed poor uniformity in the bottom quantum well region which has to be improved in future studies. Spatially and spectrally resolved CL measurements identified the origin of the emission peaks. High photoluminescence efficiency and narrow spectral width from the ridge QWR proved the achievement of high quality and high uniformity in the ridge QWR arrays, From the PL peak position which showed a large blueshift, a linear array of QWRs with an effective width of 10 nm has been successfully realized at a small wire pitch of 800 rim, Excitation power-dependence and temperature-dependence of photoluminescence have shown that the present QWR arrays are very well behaved Lip to 250 K, being free from saturation, and from surface/interface recombination processes.