Carrier Diffusion in Thin-Film CH3NH3PbI3 Perovskite Measured using Four-Wave Mixing

Abstract

We report the application of femtosecond four-wave mixing (FWM) to the study of carrier transport in solution-processed CH3NH3PbI3. The diffusion coefficient was extracted through direct detection of the lateral diffusion of carriers utilizing the transient grating technique, coupled with simultaneous measurement of decay kinetics exploiting the versatility of the boxcar excitation beam geometry. The observation of exponential decay of the transient grating versus interpulse delay indicates diffusive transport with negligible trapping within the first nanosecond following excitation. The in-plane transport geometry in our experiments enabled the diffusion length to be compared directly with the grain size, indicating that carriers move across multiple grain boundaries prior to recombination. Our experiments illustrate the broad utility of FWM spectroscopy for rapid characterization of macroscopic film transport properties.

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Cited by in corpus (5)

• Tutorial: Characterizing Microscale Energy Transport in Materials with Transient Grating Spectroscopy
• Time-resolved imaging of non-diffusive carrier transport in long-lifetime halide perovskite thin films
• Photon echo polarimetry of excitons and biexcitons in a CH${}_3$NH${}_3$PbI${}_3$ perovskite single crystal
• Ultrafast acoustic phonon scattering in CH${}_3$NH${}_3$PbI${}_3$ revealed by femtosecond four-wave mixing
• Impact of electron-phonon scattering on optical properties of CH${}_3$NH${}_3$PbI${}_3$ hybrid perovskite material