Carrier Relaxation and Lattice Heating Dynamics in Silicon Revealed by Femtosecond Electron Diffraction Export

@article{JPhysChemB2006MHarb, abstract = {Abstract: We report on the use of femtosecond electron diffraction to resolve the dynamics of electron-phonon relaxation in silicon. Nanofabricated free-standing membranes of polycrystalline silicon were excited below the damage threshold with 387 nm light at a fluence of 5.6 mJ/cm2 absorbed (corresponding to a carrier density of 2.2 × 1021 cm-3). The diffraction pattern was captured over a range of delay times with a time resolution of 350 fs. All of the detected Bragg peaks exhibited intensity loss with a time constant of less than 2 ps. Beyond the initial decay, there was no further change in the diffracted intensity up to 700 ps. We find that the loss of intensity in the diffracted orders is accounted for by the Debye-Waller effect on a time scale indicative of a thermally driven process as opposed to an electronically driven one. Furthermore, the relaxation time constant is consistent with the excitation regime where the phonon emission rate is reduced due to carrier screening.}, address = {Institute for Optical Sciences and Departments of Physics and Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada}, author = {Harb, M. and Ernstorfer, R. and Dartigalongue, T. and Hebeisen, C. T. and Jordan, R. E. and Miller, R. J. D.}, citeulike-article-id = {3318789}, citeulike-linkout-0 = {http://dx.doi.org/10.1021/jp064649n}, citeulike-linkout-1 = {http://pubs.acs.org/doi/abs/10.1021/jp064649n}, day = {21}, doi = {10.1021/jp064649n}, journal = {J. Phys. Chem. B}, keywords = {carrier-relaxation, dynamics, electron-diffraction, lattice-heating}, month = {December}, number = {50}, pages = {25308--25313}, posted-at = {2008-09-23 01:01:01}, priority = {2}, title = {Carrier Relaxation and Lattice Heating Dynamics in Silicon Revealed by Femtosecond Electron Diffraction}, url = {http://dx.doi.org/10.1021/jp064649n}, volume = {110}, year = {2006} }

TY - JOUR ID - JPhysChemB2006MHarb L3 - citeulike-article-id:3318789 N2 - Abstract: We report on the use of femtosecond electron diffraction to resolve the dynamics of electron-phonon relaxation in silicon. Nanofabricated free-standing membranes of polycrystalline silicon were excited below the damage threshold with 387 nm light at a fluence of 5.6 mJ/cm2 absorbed (corresponding to a carrier density of 2.2 × 1021 cm-3). The diffraction pattern was captured over a range of delay times with a time resolution of 350 fs. All of the detected Bragg peaks exhibited intensity loss with a time constant of less than 2 ps. Beyond the initial decay, there was no further change in the diffracted intensity up to 700 ps. We find that the loss of intensity in the diffracted orders is accounted for by the Debye-Waller effect on a time scale indicative of a thermally driven process as opposed to an electronically driven one. Furthermore, the relaxation time constant is consistent with the excitation regime where the phonon emission rate is reduced due to carrier screening. IS - 50 JF - J. Phys. Chem. B AD - Institute for Optical Sciences and Departments of Physics and Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada EP - 25313 TI - Carrier Relaxation and Lattice Heating Dynamics in Silicon Revealed by Femtosecond Electron Diffraction VL - 110 SP - 25308 KW - carrier-relaxation KW - dynamics KW - electron-diffraction KW - lattice-heating AU - Harb, M AU - Ernstorfer, R AU - Dartigalongue, T AU - Hebeisen, CT AU - Jordan, RE AU - Miller, RJD PY - 2006/12/21/ UR - http://dx.doi.org/10.1021/jp064649n ER -