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Recombination Dynamics in Thin-film Photovoltaic Materials via Time-resolved Microwave Conductivity
Published on: March 6, 2017
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Evidence for Bootstrap Percolation Dynamics in a Photoinduced Phase Transition
Tyler Carbin1, Xinshu Zhang1, Adrian B Culver1,2
1Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095-1547, USA.
Physical Review Letters
|May 19, 2023
Summary
Intense light can trigger phase transitions in materials. This study reveals that nanoscale variations significantly impact the speed of these photoinduced phase transitions in Ca3Ru2O7.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Ultrafast Spectroscopy
Background:
- Understanding nonequilibrium phase transitions is crucial for materials science.
- Femtosecond photoexcitation offers a route to induce such transitions.
- The role of mesoscale inhomogeneity in these dynamics is not well understood.
Purpose of the Study:
- To investigate the influence of mesoscale inhomogeneity on photoinduced phase transitions.
- To study the dynamics of phase transition in Ca3Ru2O7 using time-resolved second harmonic generation.
- To develop a model for understanding the kinetics of photoinduced phase transitions.
Main Methods:
- Time-resolved second harmonic generation spectroscopy to probe structural changes.
- Femtosecond laser pulses for photoexcitation.
- Bootstrap percolation simulations to model transition kinetics.
Main Results:
- Observed a significant slowing down of the photoinduced phase transition in Ca3Ru2O7.
- The characteristic transition time (τ) showed nonmonotonic dependence on photoexcitation fluence, ranging from sub-200 fs to ~1.4 ps.
- Bootstrap percolation simulations successfully reproduced the observed transition dynamics, highlighting the role of local interactions.
Conclusions:
- Mesoscale inhomogeneity profoundly influences the dynamics of photoinduced phase transitions.
- Percolation effects in inhomogeneous systems are critical for understanding transition kinetics.
- The developed model provides a framework for studying similar transitions in other materials.
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