Novel InGaAs/GaAs quantum dot structures formed in tetrahedral-shaped recesses on (111)B GaAs substrate using metalorganic vapor phase epitaxy

We report a novel GaAs/InGaAs/GaAs quantum dot structure formed in a tetrahedral-shaped recess (TSR) patterned on a (111)B GaAs substrate with anisotropic chemical etching. The pseudomorphic heterostructure shows two clear photoluminescence peaks which are attributed to an In anisotropic incorporation on (111)B compared to (111)A. Cathodoluminescence at a lower energy peak with InGaAs of 2.5 nm shows a bright image at the bottom of TSRs which indicates the local minimum in potential energy at the bottom of TSR.