Excited carrier dynamics of alpha-Cr2O3/alpha-Fe2O3 core-shell nanostructures.
In this work alpha-Cr(2)O(3)/alpha-Fe(2)O(3) core-shell polycrystalline nanostructures were synthesized by using alpha-Cr(2)O(3) nanoparticles as seed crystals during aqueous nucleation. The formation of alpha-Fe(2)O(3) polycrystallites on alpha-Cr(2)O(3) surfaces was confirmed by X-ray diffraction, transmission electron microscopy, and energy-dispersive X-ray analysis. The excited-state relaxation dynamics of as-grown core-shell structures and "pure" alpha-Fe(2)O(3) particles of the same size were measured with femtosecond transient absorption spectroscopy. The results show the carrier lifetimes decay within a few picoseconds regardless of sample. This is likely due to fast recombination/trapping of carriers to defects and iron d-states.
Xiong
Gang
G
Pacific Northwest National Laboratory, P.O. Box 999, K8-88, Richland, Washington 99352, USA.
Joly
Alan G
AG
Holtom
Gary P
GP
Wang
Chongmin
C
McCready
David E
DE
Beck
Kenneth M
KM
Hess
Wayne P
WP