Trimming the size of InAs/InP quantum dots grown by CBE

We have used transmission electron microscopy and low temperature photoluminescence to study the growth by chemical beam epitaxy of self-assembled InAs/InP quantum dots. Square dots 30-40 nm in width were grown with a density of 10/sup 10/ cm/sup -2/. By partially covering the dots with InP and exposing them to a phosphorus overpressure the mean height of the dots, and hence their emission energies, could be controlled. The emission energy was found to be strongly dependent on the amount of InP used to partially cover the InAs dots, but only weakly dependent on the phosphorus exposure time for times greater than 15 sec.