TUNABLE INTERSUBLEVEL TRANSITIONS IN SELF-FORMING SEMICONDUCTOR QUANTUM DOTS

Interfacial compositional disordering in In0.6Ga0.4As/GaAs quantum dot s has been used to tune their intersublevel energy spacings (Delta E[( i+1-i])). Interdiffusion blueshifted all levels while lowering values for Delta E[(i+1-i]). Rate equation simulations of photoluminescence ( PL) spectra estimated relaxation lifetime ratios for intersublevel tra nsitions. A slight trend towards increasing thermalization rates at va lues Delta E[(i+1-i]) similar to LO phonon energies was found. However , PL measurements showed strong emission from excited states for all D elta E[(i+1-i]) values, which ranged from 53 to 25 meV.