Carrier Dynamics in a-Fe2O3 (0001) Thin Films and Single Crystals Probed by Femtosecond Transient Absorption and Reflectivity

Journal Article · Wed Mar 01 04:00:00 EST 2006 · Journal of Applied Physics, 99(5):Article: 053521 (6 pages)

DOI:https://doi.org/10.1063/1.2177426· OSTI ID:882953

Joly, Alan G; Williams, Josh R; Chambers, Scott A; Xiong, Gang; Hess, Wayne P; Laman, David M

Femtosecond transient reflectivity and absorption is used to measure the carrier lifetimes in α-Fe2O3 thin films and hematite single crystals. The results from the thin films show that initially excited hot electrons relax to the bandedge within 300 femtoseconds and then recombine with holes or trap within 5 pioseconds. The trapped electrons have a lifetime of hundreds of picoseconds. The trapped electrons have a lifetime of hundreds of picoseconds. Transient reflectivity measurements from hematite (α-Fe2O3) single crystals show similar but slightly faster dynamics. In hematite, the transient reflectivity displays oscillations due to the formation of longitudinal acoustic phonons generated following absorption of the ultrashort excitation pulse.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 882953
• Report Number(s): PNNL-SA-45700; 11105; KC0302010
• Journal Information: Journal of Applied Physics, 99(5):Article: 053521 (6 pages), Journal Name: Journal of Applied Physics, 99(5):Article: 053521 (6 pages)
• Country of Publication: United States
• Language: English

Related Subjects

Environmental Molecular Sciences Laboratory