Femtosecond carrier dynamics of semiconductors such as PbI2 and CH3NH3PbI3 are measured using tabletop high-harmonic extreme ultraviolet (XUV) transient absorption spectroscopy. XUV absorption from 45-65 eV measures transitions from the iodine 4d core level to the conduction band density of states. Photoexcitation with visible light creates separate and distinct transient absorption signals for holes and electrons, separated in energy by the band gap of the semiconductor. Furthermore, the shape of the transient signal measures the carrier temperature. Finally, we use the element specificity of this technique to track electron and hole transfer from the perovskite absorber into TiO2 and NiO charge collection layers.

Carrier-specific femtosecond extreme ultraviolet spectroscopy of semiconductors

254th National Meeting (2017)

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