Abstract
We use first-principles models to demonstrate how an organic oxidizing agent F-TCNQ (7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane) modifies the electronic structure of silicon nanocrystals, suggesting it may enhance -type carrier density and mobility. The proximity of the lowest unoccupied level of F-TCNQ to the highest occupied level of the Si nanocrystals leads to the formation of an empty hybrid state overlapping both the nanocrystal and molecule, reducing the excitation energy to 0.8–1 eV in vacuum. Hence, it is suggested that F-TCNQ can serve both as a surface oxidant and as a mediator for hole hopping between adjacent nanocrystals in -type doped silicon nanocrystal networks.
- Received 28 July 2011
DOI:https://doi.org/10.1103/PhysRevB.84.125437
©2011 American Physical Society