OPTICAL CHARACTERIZATION OF INGAAS GAAS QUANTUM DOTS DEFINED BY LATERAL TOP BARRIER MODULATION/

We have produced effectively buried quantum well dots on the basis of InGaAs/GaAs single quantum wells using high resolution electron beam l ithography and selective wet etching of the top barrier. The lateral b arriers are realized by the difference in quantization energy in quant um wells with a semiconductor top barrier compared to quantum wells wi th a vacuum potential barrier. Dot structures with widths down to 20 n m have been generated. We observe that the structures maintain high lu minescence efficiencies down to the smallest sizes. We also observe a blueshift of up to 9 meV for 23 nm quantum dots. High excitation photo luminescence shows a second lateral subband in small dot structures.