Cu(I) - Doping Induced Suppression of Multiexciton Auger Recombination in CdS Quantum Dots

Metal chalcogenide quantum dots (QDs) are attractive because of their application in photovoltaics and light emitting devices (LEDs). Non-radiative Auger recombination is a major hindrance in this regard. Doping with metal ions is an effective modality to overcome this issue. In the present work, the effect of Cu(I) doping in supressing the nonradiative Auger recombination in MPA-capped CdS QDs in aqueous medium is examined as is evidenced by ultrafast transient absorption spectroscopy and femtosecond optical gating. Doped QDs have shown a significant longer bi-exciton lifetime. This observation has proven that hole trapping to dopant energy level reduce the Auger process. This comparative study elucidates the understanding and set the practical guidelines for controlling the multicarrier Auger recombination in similar QDs.