Repairing Nanoparticle Surface Defects

Angewandte Chemie - International Edition

4 years ago

Repairing Nanoparticle Surface Defects

Ryan W. Crisp, Emanuele Marino, Marc Heggen, Katherine E. MacArthur, Thomas E. Kodger, Peter Schall, Dolf Timmerman

Solar devices based on semiconductor nanoparticles require the use of conductive ligands; however, replacing the native, insulating ligands with conductive metal chalcogenide complexes introduces structural defects within the crystalline nanostructure that act as traps for charge carriers. We utilized atomically thin semiconductor nanoplatelets as a convenient platform for studying, both microscopically and spectroscopically, the development of defects during ligand exchange with the conductive ligands Na4SnS4 and (NH4)4Sn2S6. These defects can be repaired via mild chemical or thermal routes, through the addition of L-type ligands or wet annealing, respectively. This results in a higher-quality, conductive, colloidally stable nanomaterial that may be used as the active film in optoelectronic devices. Solar devices based on semiconductor nanoparticles require the use of conductive ligands; however, the exchange of insulating ligands with conductive metal chalcogenide complexes introduces structural defects that act as traps for charge carriers. CdSe nanoplatelets were used as a model system to show that it is possible to minimize the formation of defects, as well as trigger surface healing, by a judicious choice of mild treatments.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/anie.201705685