BiVO4 is a promising material for solar energy conversion applications. However, it suffers from low mobility due to strong carrier-phonon coupling, which favors formation of polarons. To elucidate carrier transport mechanisms in BiVO4, we apply time-resolved THz spectroscopy to probe dynamics of photexcited carriers and their coupling to lattice vibrational modes at early times (1-20 ps) after photoexcitation. We find that at high excitation fluences, trap states are saturated and a short-lived population of highly mobile residual carriers exists. At the same time, saturation of hole trap states manifests itself in changes in the low-frequency (1.92 THz) seesaw phonon mode between the Bi and VO4 units.
|Title of host publication||41st International Conference on Infrared, Millimeter and Terahertz Waves, IRMMW-THz 2016|
|Publisher||IEEE Computer Society|
|State||Published - 28 Nov 2016|
|Event||41st International Conference on Infrared, Millimeter and Terahertz Waves, IRMMW-THz 2016 - Copenhagen, Denmark|
Duration: 25 Sep 2016 → 30 Sep 2016
|Name||International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz|
|Conference||41st International Conference on Infrared, Millimeter and Terahertz Waves, IRMMW-THz 2016|
|Period||25/09/16 → 30/09/16|
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