Effect of Quantum Confinement and Lattice Relaxation on Electronic States in GaAs/In 0.2Ga 0.8As/GaAs Quantum Dots

The effect of quantum confinement and lattice relaxation on electronic states in GaAs/In 0.2 Ga 0.8 As/GaAs quantum dots has been studied. The quantum dots were fabricated using electron beam lithography and wet chemical etching, and photoluminescence measurements were carried out to investigate the electronic states of the dots. A blue shift in the transition energy for smaller quantum dots was clearly observed, while the transition energy shifts to lower energy for larger dots. The blue shift is attributed to quantum confinement and the red shift to lattice relaxation. A simple empirical formula is given which well describes the observed energy shift.