We demonstrated that the lattice-matched GaAs quantum nanodisks (QNDs) embedded in an AlGaAs matrix were fabricated by our original topdown nanoprocess. Lattice-matched GaAs QNDs are very attractive in quantum cryptography because the spin relaxation time of QNDs might be longer than that of strained quantum dots. Quantum levels of QNDs were investigated by the photoluminescence (PL) technique. The minimum diameter and thickness of QNDs were 7 and 8 nm, respectively. PL peaks of QNDs at 1.64 and 1.66 eV were observed to be higher than that of multiple quantum wells (MQWs) observed at 1.57 eV. It is suggested that these peaks are due to the diameter distribution of QNDs. The calculated quantum levels were in good agreement with the present experimental results. The observation of the PL peaks from QNDs demonstrates that the quantum level is strongly confined not only in the perpendicular direction but also in the lateral direction.
ASJC Scopus subject areas
- Physics and Astronomy(all)