Size control of self-assembled quantum wires for emission wavelength engineering

It is now well established (1-5) that nanowires formation along [11~0] takes place when an InAs thin layer (about 2.7 monolayers, ML) is grown by MBE on InP [001] substrate. Strain relaxation is the driving force for the unidirectional observed surface roughening due to the asymmetric accumulated stress induced during MBE growth of a lattice mismatch III-V/III-V\´ heteroepitaxial system. In the case of InAs/InP[001] system, the nanowires covered with an InP cap layer produce photoluminescence (PL) emission at /spl lambda//spl ap/1.5 /spl mu/m at room temperature. However it should be desirable to exactly tune the emission wavelength to the optimum for communication devices (/spl lambda/=1.55 /spl mu/m) as well as to any other wavelength under design. In this work we have grown by MBE samples consisting of In/sub 1-x/Ga/sub x/As and In/sub 1-x/Al/sub x/As (O\n\n\t\t