Efficient generation of emissive many-body correlations in copper-doped colloidal quantum wells
Junhong Yu, Manoj Sharma, Mingjie Li, Baiquan Liu, Pedro Ludwig Hernández‐Martínez, Savas Delikanli, Ashma Sharma, Yemliha Altıntas, Chathuranga Hettiarachchi, Tze Chien Sum, Hilmi Volkan Demir, Cuong Dang
Abstract
Colloidal quantum wells (CQWs) provide an appealing platform to achieve emissive many-body correlations for novel optoelectronic devices, given that they act as hosts for strong carrier Coulomb interactions and present suppressed Auger recombination. However, the demonstrated high-order excitonic emission in CQWs requires ultrafast pumping with high excitation levels and can only be spectrally resolved at the single-particle level under cryogenic conditions. Here, through systematic investigation using static power-dependent emission spectroscopy and transient carrier dynamics, we show that Cu-doped CdSe CQWs exhibit continuous-wave-pumped high-order excitonic emission at room temperature with a large binding energy of ∼64 meV. We attribute this unique behavior to dopant excitons in which the ultralong lifetime and the highly localized wavefunction facilitate the formation of many-body correlations. The spectrally resolved high-order excitonic emission generated at power levels compatible with solar irradiation and electrical injection might pave the way for novel solution-processed solid-state devices.