Ultrafast carrier dynamics in BiVO4

Interplay between free carriers, trapped carriers and low-frequency lattice vibrations

Benjamin J. Dringoli, Keith T. Butler, Lite Zhou, Binod Giri, Pratap M. Rao, A. Walsh, Lyubov V. Titova

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

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.

Original languageEnglish
Title of host publication41st International Conference on Infrared, Millimeter and Terahertz Waves, IRMMW-THz 2016
PublisherIEEE Computer Society
Volume2016-November
ISBN (Electronic)9781467384858
DOIs
Publication statusPublished - 2016 Nov 28
Event41st International Conference on Infrared, Millimeter and Terahertz Waves, IRMMW-THz 2016 - Copenhagen, Denmark
Duration: 2016 Sep 252016 Sep 30

Other

Other41st International Conference on Infrared, Millimeter and Terahertz Waves, IRMMW-THz 2016
CountryDenmark
CityCopenhagen
Period16/9/2516/9/30

Fingerprint

Hole traps
Polarons
Lattice vibrations
Carrier transport
Photoexcitation
Energy conversion
Solar energy
Spectroscopy

All Science Journal Classification (ASJC) codes

  • Energy Engineering and Power Technology
  • Electrical and Electronic Engineering

Cite this

Dringoli, B. J., Butler, K. T., Zhou, L., Giri, B., Rao, P. M., Walsh, A., & Titova, L. V. (2016). Ultrafast carrier dynamics in BiVO4: Interplay between free carriers, trapped carriers and low-frequency lattice vibrations. In 41st International Conference on Infrared, Millimeter and Terahertz Waves, IRMMW-THz 2016 (Vol. 2016-November). [7758784] IEEE Computer Society. https://doi.org/10.1109/IRMMW-THz.2016.7758784
Dringoli, Benjamin J. ; Butler, Keith T. ; Zhou, Lite ; Giri, Binod ; Rao, Pratap M. ; Walsh, A. ; Titova, Lyubov V. / Ultrafast carrier dynamics in BiVO4 : Interplay between free carriers, trapped carriers and low-frequency lattice vibrations. 41st International Conference on Infrared, Millimeter and Terahertz Waves, IRMMW-THz 2016. Vol. 2016-November IEEE Computer Society, 2016.
@inproceedings{9b47924544434556a2de1714e69b667b,
title = "Ultrafast carrier dynamics in BiVO4: Interplay between free carriers, trapped carriers and low-frequency lattice vibrations",
abstract = "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.",
author = "Dringoli, {Benjamin J.} and Butler, {Keith T.} and Lite Zhou and Binod Giri and Rao, {Pratap M.} and A. Walsh and Titova, {Lyubov V.}",
year = "2016",
month = "11",
day = "28",
doi = "10.1109/IRMMW-THz.2016.7758784",
language = "English",
volume = "2016-November",
booktitle = "41st International Conference on Infrared, Millimeter and Terahertz Waves, IRMMW-THz 2016",
publisher = "IEEE Computer Society",
address = "United States",

}

Dringoli, BJ, Butler, KT, Zhou, L, Giri, B, Rao, PM, Walsh, A & Titova, LV 2016, Ultrafast carrier dynamics in BiVO4: Interplay between free carriers, trapped carriers and low-frequency lattice vibrations. in 41st International Conference on Infrared, Millimeter and Terahertz Waves, IRMMW-THz 2016. vol. 2016-November, 7758784, IEEE Computer Society, 41st International Conference on Infrared, Millimeter and Terahertz Waves, IRMMW-THz 2016, Copenhagen, Denmark, 16/9/25. https://doi.org/10.1109/IRMMW-THz.2016.7758784

Ultrafast carrier dynamics in BiVO4 : Interplay between free carriers, trapped carriers and low-frequency lattice vibrations. / Dringoli, Benjamin J.; Butler, Keith T.; Zhou, Lite; Giri, Binod; Rao, Pratap M.; Walsh, A.; Titova, Lyubov V.

41st International Conference on Infrared, Millimeter and Terahertz Waves, IRMMW-THz 2016. Vol. 2016-November IEEE Computer Society, 2016. 7758784.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

TY - GEN

T1 - Ultrafast carrier dynamics in BiVO4

T2 - Interplay between free carriers, trapped carriers and low-frequency lattice vibrations

AU - Dringoli, Benjamin J.

AU - Butler, Keith T.

AU - Zhou, Lite

AU - Giri, Binod

AU - Rao, Pratap M.

AU - Walsh, A.

AU - Titova, Lyubov V.

PY - 2016/11/28

Y1 - 2016/11/28

N2 - 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.

AB - 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.

UR - http://www.scopus.com/inward/record.url?scp=85006168224&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85006168224&partnerID=8YFLogxK

U2 - 10.1109/IRMMW-THz.2016.7758784

DO - 10.1109/IRMMW-THz.2016.7758784

M3 - Conference contribution

VL - 2016-November

BT - 41st International Conference on Infrared, Millimeter and Terahertz Waves, IRMMW-THz 2016

PB - IEEE Computer Society

ER -

Dringoli BJ, Butler KT, Zhou L, Giri B, Rao PM, Walsh A et al. Ultrafast carrier dynamics in BiVO4: Interplay between free carriers, trapped carriers and low-frequency lattice vibrations. In 41st International Conference on Infrared, Millimeter and Terahertz Waves, IRMMW-THz 2016. Vol. 2016-November. IEEE Computer Society. 2016. 7758784 https://doi.org/10.1109/IRMMW-THz.2016.7758784