Anti-Stokes photoluminescence of InP self-assembled quantum dots in the presence of electric current

An intense anti-Stokes photoluminescence was observed in a structure with I nP quantum dots (QD's) in the presence of both a direct electric current an d optical pumping below the lowest electron-hole transition in quantum dots . The discovered phenomenon provides clear evidence of deep energy levels i n the vicinity of the QD's. A simple model was proposed which allowed us to estimate the energies of the deep states and the lower limit of the produc t of the electron and hole relaxation rates from the QD's to the deep state s. [S0163-1829(99)51744-X].