Size-dependent properties of single InAs quantum dots grown in nanoimprint lithography patterned GaAs pits.

We report on the structural and optical properties of single InAs quantum dots (QDs) formed in etched GaAs pits with different dimensions. The site-controlled QDs were fabricated by molecular beam epitaxy on GaAs(001) surfaces patterned by nanoimprint lithography. We show that the properties of the QDs can be modified by varying the dimensions of the etched GaAs pits. Increasing the pit size resulted in larger QDs and thus in longer photoluminescence wavelengths. However, the fine structure splitting remained unaffected. A photoluminescence linewidth of 41 μeV and average fine structure splitting of 15.7 μeV were obtained for exciton recombination in the single site-controlled QDs.