Damping of Cu-Associated Photoluminescence and Formation of Induced Absorption in Heavily Cu-Doped CdSe Quantum Dots

We studied photoluminescence (PL) properties and nonlinear absorption characteristics of heavily Cu-doped CdSe colloidal quantum dots (QDs) under nanosecond laser pulse excitation. A strong dependence of basic exciton transition behavior and Cu dopant-associated PL on the concentration of copper ions and pump intensities was revealed for the first time. The saturation of the copper-associated PL signal was found to happen much faster than the saturation of nonlinear absorption. The induced absorption and saturation of high energy transitions due to the exciton–exciton interaction were investigated in Cu-doped CdSe QDs. The obtained results could be useful for the development of optoelectronic devices operating at room temperature on the basis of Cu-doped colloidal QDs.