Luminescence Hole Burning and Quantum Size Effect of Charged Excitons in CuCl Quantum Dots

Luminescence hole-burning phenomena were observed in CuCl quantum dots embedded in a NaCl crystal. As a result of the selective excitation of the $Z_3$ exciton band of CuCl quantum dots, a resonantly burned hole and moreover its sidebands appear in the luminescence spectrum. The Stokes shift of the sidebands increases with the increase in the burning photon energy, and its dependence is explained by the quantum size effect of the negatively charged exciton $X^{-}$ and the positively charged exciton $X_2^{+}$. New exciton complexes, $X^{-}$ and $X_2^{+}$, confined in quantum dots were first observed by the luminescence hole burning.