Quantum-confined biexcitons in CuCl quantum dots and their unconventional optical properties

Abstract

The optical properties of quantum-confined biexcitons in CuCl quantum dots (QDs) under the novel method of two-photon resonance excitation of biexcitons are reviewed. First, we briefly overview the optical properties of excitons and biexcitons in bulk CuCl single crystals and also those in quantum dots, and then we cover the biexcitonic properties of CuCl quantum dots in NaCl matrices in detail: realization of two-photon resonant excitation of confined biexcitons with different angular momenta, studies on the energy-level structure of biexcitonic states by size-selective two-photon resonant excitation of biexcitons, on subsequent efficient lasing of biexcitonic luminescence even in low-Q cavity, on ultrafast radiative decay of biexcitons, and, finally, the observation of excited states of confined biexcitons studied by infrared transient absorption. All these unconventional features are inherent in the biexcitons in CuCl QDs affected by quantum confinement effects.

Model for a biexciton in a lateral quantum dot based on exact solutions for the Hookean H2 molecule. I. Theoretical aspects

“…Calculations have been performed to determine the binding energies of excitonic complexes as a function of the quantum dot height [29] and length [30]. Also, the size of quantum dots in which biexcitons are generated under a two‐photon resonant excitation, has been determined [31].…”