Photoinduced Surface Charging in Iron-Carbonyl-Functionalized Colloidal Semiconductor Nanocrystals
2019; 19 (11): 7770-7774
Organometallic surface functionalization of colloidal CdSe and CdS nanocrystals using iron tetracarbonyl moieties is demonstrated to enable study of in situ colloidal nanocrystal surface redox chemistry. Spectroscopic measurements of the surface-bound metal carbonyl C-O stretches were used to elucidate the coordination environments and local symmetry of surface sites. The C-O stretching frequencies of these fragments were correlated to the electric field induced by nanocrystal surface charges and shift in energy upon surface reduction or oxidation. These measurements revealed that CdSe nanocrystals can accumulate multiple surface electrons under supra-band gap photoexcitation, a process likely relevant to photoactivated nanocrystal processes such as photobrightening. These surface charges are stable for hours and decay extremely slowly under anaerobic conditions.
View details for DOI 10.1021/acs.nanolett.9b02726
View details for Web of Science ID 000497259300024
View details for PubMedID 31596596