Colloidal Mn2+ doped semiconductor nanocrystals are quantum confined, solution processable analogs of classic diluted magnetic semiconductor materials whose novel optical and magnetic properties have promising applications in photonics, spintronics, and quantum computing. In these doped nanocrystals, sp-d exchange interactions between magnetic dopants and carriers give rise to an interdependence of dopant spins and semiconductor electronic structure. This work aims to elucidate the complexity of this relationship by exploring both the effect of dopant spins on carriers and the influence of carrier spins on dopants. For example, magnetic dopants give rise to giant Zeeman splitting of excitonic states, and it has also been demonstrated that electrons in Mn2+-doped ZnO break the antiferromagnetic exchange interactions within dopant pairs. In the process of excitonic magnetic polaron (EMP) formation in Mn2+-doped CdSe nanocrystals, dopants and carriers are affected by each other: photoexcitation causes Mn2+ spins to align, which then generates internal fields strong enough to substantially redshift the photoluminescence. Through a variety of time-resolved and continuous-wave magneto-optical spectroscopy techniques, we investigate the factors that determine the orientation, coherence, and time evolution of excitonic magnetic polarons as an example of the complex interplay between magnetic dopants and carriers.

Exchange interactions in colloidal magnetically doped semiconductor nanocrystals

248th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.