Abstract
The structural and electronic recovery pathways of a photoexcited ultrathin vanadium dioxide (VO2) film at nanosecond time scales have been studied using time-resolved x-ray diffraction and transient optical absorption techniques. The recovery pathways from the tetragonal metallic phase to the monoclinic insulating phase are highly dependent on the optical pump fluence. At pump fluences higher than the saturation fluence of 14.7 mJ/cm2, we observed a transient structural state with lattice parameter larger than that of the tetragonal phase, which is decoupled from the metal-to-insulator phase transition. Subsequently, the photoexcited VO2 film recovered to the ground state at characteristic times dependent upon the pump fluence as a result of heat transport from the film to the substrate. We present a procedure to measure the time-resolved film temperature by correlating photoexcited and temperature-dependent x-ray diffraction measurements. A thermal transport model that incorporates changes of the thermal parameters across the phase transition reproduces the observed recovery dynamics. The optical excitation and fast recovery of ultrathin VO2 films provides a practical method to reversibly switch between the monoclinic insulating and tetragonal metallic state at nanosecond time scales.
| Original language | English |
|---|---|
| Article number | 165424 |
| Journal | Physical Review B - Condensed Matter and Materials Physics |
| Volume | 88 |
| Issue number | 16 |
| DOIs | |
| Publication status | Published - Oct 25 2013 |
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ASJC Scopus subject areas
- Condensed Matter Physics
- Electronic, Optical and Magnetic Materials
Cite this
Structural and electronic recovery pathways of a photoexcited ultrathin VO2 film. / Wen, Haidan; Guo, Lu; Barnes, Eftihia; Lee, June Hyuk; Walko, Donald A.; Schaller, Richard D; Moyer, Jarrett A.; Misra, Rajiv; Li, Yuelin; Dufresne, Eric M.; Schlom, Darrell G.; Gopalan, Venkatraman; Freeland, John W.
In: Physical Review B - Condensed Matter and Materials Physics, Vol. 88, No. 16, 165424, 25.10.2013.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Structural and electronic recovery pathways of a photoexcited ultrathin VO2 film
AU - Wen, Haidan
AU - Guo, Lu
AU - Barnes, Eftihia
AU - Lee, June Hyuk
AU - Walko, Donald A.
AU - Schaller, Richard D
AU - Moyer, Jarrett A.
AU - Misra, Rajiv
AU - Li, Yuelin
AU - Dufresne, Eric M.
AU - Schlom, Darrell G.
AU - Gopalan, Venkatraman
AU - Freeland, John W.
PY - 2013/10/25
Y1 - 2013/10/25
N2 - The structural and electronic recovery pathways of a photoexcited ultrathin vanadium dioxide (VO2) film at nanosecond time scales have been studied using time-resolved x-ray diffraction and transient optical absorption techniques. The recovery pathways from the tetragonal metallic phase to the monoclinic insulating phase are highly dependent on the optical pump fluence. At pump fluences higher than the saturation fluence of 14.7 mJ/cm2, we observed a transient structural state with lattice parameter larger than that of the tetragonal phase, which is decoupled from the metal-to-insulator phase transition. Subsequently, the photoexcited VO2 film recovered to the ground state at characteristic times dependent upon the pump fluence as a result of heat transport from the film to the substrate. We present a procedure to measure the time-resolved film temperature by correlating photoexcited and temperature-dependent x-ray diffraction measurements. A thermal transport model that incorporates changes of the thermal parameters across the phase transition reproduces the observed recovery dynamics. The optical excitation and fast recovery of ultrathin VO2 films provides a practical method to reversibly switch between the monoclinic insulating and tetragonal metallic state at nanosecond time scales.
AB - The structural and electronic recovery pathways of a photoexcited ultrathin vanadium dioxide (VO2) film at nanosecond time scales have been studied using time-resolved x-ray diffraction and transient optical absorption techniques. The recovery pathways from the tetragonal metallic phase to the monoclinic insulating phase are highly dependent on the optical pump fluence. At pump fluences higher than the saturation fluence of 14.7 mJ/cm2, we observed a transient structural state with lattice parameter larger than that of the tetragonal phase, which is decoupled from the metal-to-insulator phase transition. Subsequently, the photoexcited VO2 film recovered to the ground state at characteristic times dependent upon the pump fluence as a result of heat transport from the film to the substrate. We present a procedure to measure the time-resolved film temperature by correlating photoexcited and temperature-dependent x-ray diffraction measurements. A thermal transport model that incorporates changes of the thermal parameters across the phase transition reproduces the observed recovery dynamics. The optical excitation and fast recovery of ultrathin VO2 films provides a practical method to reversibly switch between the monoclinic insulating and tetragonal metallic state at nanosecond time scales.
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U2 - 10.1103/PhysRevB.88.165424
DO - 10.1103/PhysRevB.88.165424
M3 - Article
VL - 88
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 1098-0121
IS - 16
M1 - 165424
ER -