TY - JOUR
T1 - Ultrafast terahertz spectroscopy provides insight into charge transfer efficiency and dynamics in artificial photosynthesis
AU - Tayvah, Uriel T.
AU - Neu, Jens
AU - Spies, Jacob A.
AU - Schmuttenmaer, Charles A.
AU - Brudvig, Gary W.
N1 - Funding Information:
This work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences (DE-FG02-07ER15909). U.T.T. acknowledges the support of the National Science Foundation Graduate Research Fellowship (DGE-1752134).
PY - 2020
Y1 - 2020
N2 - Terahertz (THz) spectroscopy provides a noncontact method to measure the ultrafast dynamics and photoconductivity of mobile carriers in semiconducting materials. This has proven useful in studying artificial photosynthesis devices which use semiconductor photoelectrodes. We present a brief introduction to optical-pump THz-probe (OPTP) spectroscopy, a technique that provides unique and useful insight into interfacial electron transfer (from the surface-attached dye to the conduction band of the semiconductor) in dye-sensitized photoelectrochemical cells. Compared with more familiar methods like visible transient absorption spectroscopy, OPTP spectroscopy stands out in offering both sub-picosecond time resolution as well as sensitivity to mobile carriers (electrons and holes) in the semiconductor portion of artificial photosynthesis devices. The mobile carriers are crucial to device performance as only they pass to the other half cell to complete the reaction. In order to highlight these advantages and illustrate the types of questions OPTP spectroscopy can address, we discuss three case studies. In the first, OPTP spectroscopy is used to measure the injection rates from a set of six different dyes, revealing the effect of the energetics and lifetimes of the dye excited states on interfacial electron transfer. The subsequent case studies investigate the influence of varying the moieties which bind to the surface (anchors), as well as the moieties that connect the chromophore with these anchors (linkers). OPTP spectroscopy was used to measure the interfacial electron transfer rate as these moieties were varied.
AB - Terahertz (THz) spectroscopy provides a noncontact method to measure the ultrafast dynamics and photoconductivity of mobile carriers in semiconducting materials. This has proven useful in studying artificial photosynthesis devices which use semiconductor photoelectrodes. We present a brief introduction to optical-pump THz-probe (OPTP) spectroscopy, a technique that provides unique and useful insight into interfacial electron transfer (from the surface-attached dye to the conduction band of the semiconductor) in dye-sensitized photoelectrochemical cells. Compared with more familiar methods like visible transient absorption spectroscopy, OPTP spectroscopy stands out in offering both sub-picosecond time resolution as well as sensitivity to mobile carriers (electrons and holes) in the semiconductor portion of artificial photosynthesis devices. The mobile carriers are crucial to device performance as only they pass to the other half cell to complete the reaction. In order to highlight these advantages and illustrate the types of questions OPTP spectroscopy can address, we discuss three case studies. In the first, OPTP spectroscopy is used to measure the injection rates from a set of six different dyes, revealing the effect of the energetics and lifetimes of the dye excited states on interfacial electron transfer. The subsequent case studies investigate the influence of varying the moieties which bind to the surface (anchors), as well as the moieties that connect the chromophore with these anchors (linkers). OPTP spectroscopy was used to measure the interfacial electron transfer rate as these moieties were varied.
KW - Artificial photosynthesis
KW - Charge transfer
KW - Terahertz spectroscopy
KW - Ultrafast
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U2 - 10.1007/s11120-020-00798-9
DO - 10.1007/s11120-020-00798-9
M3 - Article
AN - SCOPUS:85096319903
JO - Photosynthesis Research
JF - Photosynthesis Research
SN - 0166-8595
ER -