Controlling emission wavelength from InAs self-assembled quantum dots on InP (0 0 1) during MOCVD

We studied the growth of InAs quantum dots on InP (0 0 1) substrates in a low-pressure metalorganic chemical vapor deposition by using a so-called InP ‘double-cap’ procedure. With double-capping, a photoluminescence spectrum is modified into a series of multiple peaks, where the emission peaks arise from several quantum dot families with different heights changing in a step of integer number of an InAs monolayer. Cross-sectional transmission electron micrograph observations revealed that the shape of double-capped dots is dramatically changed into a thin plate-like shape with extremely flat upper and lower interfaces, being consistent with our interpretation of the photoluminescence spectrum. We showed that the procedure was extremely useful for controlling the emission wavelength from quantum dots in an InAs/InP (0 0 1) system.