Density of states of a quantum dot array probed by photoluminescence spectra

Magneto-photoluminescence (PL) spectra of lateral quantum dots (QDs) defined by the field-effect of the surface gate structure with holes localized on acceptors are investigated. The peaks due to the Landau levels at VB=0 V at 2 T are found to change to the step wise PL line shape at VB=−0.9 V indicating zero-dimensional confinement. The PL spectra are compared with self-consistently calculated density of states and optical transition probabilities. It is found that the PL measurement of the QD array is an effective tool to probe the density of states as long as the applied bias voltage is weak.