Solar energy conversion functions often depend on dynamic structures in so­lution or on a supporting matrix where a transiently appearing dynamic structure could evolve into a precursor for catalytic intermediates. Such dy­namic structures are implicitly depicted by the Debye-Weller factor in the conventional XAS data analysis in Equation (12.1), without specific description of the structural […]

As the time resolution improves, experimental observation approaches direct visualization of nuclear motions during the photoexcitation, which provides the basis for structural control of light-matter interactions in solar energy conversion. The excited state to final photochemical product trajectories are often initiated by vibrational motions. When photons add energy to molecules, their energy will be dissipated […]

As shown in Equation (12.2), the accuracy of simultaneously and independently obtaining fractions of the transient species and their corresponding transient spectra can be challenging. Current approaches using MIA and MXAN have accomplished the first steps. The requirement is to combine these approaches with accurate potential energy surfaces around metal centers, which by itself is […]

Increasing numbers of groups are now engaging in calculations of excited state structural dynamics from first principles in isolated molecular systems and with relatively small molecules of light elements.162 165 However, only very limited calculations of excited state structural dynamics with heavy elements are available; these calculations provide not only excited state structures but also […]

Most current XTA studies are on the transient structures of excited states that are directly generated by photons through ground to excited state transitions. In solar energy conversion processes, such as photocatalysis, the most inter­esting structures to be determined are often those resulting from the excited state, such as a photocatalyst-substrate complex and other intermediate […]

Solar energy conversion processes start from photon-matter interactions and a photon triggered chemical reaction almost always generates changes in nuclear geometry of those involved. The availability of high repetition rate, intense and femtosecond hard X-ray pulses could enable the visualization of nuclear geometry evolution in many light-induced reactions in solar energy conversion processes, including ‘‘the […]

A decade of development of XTA has transformed transient structural de­termination from a fantasy to somewhat routine measurements. However, its contributions to solar energy research as well as our fundamental under­standing of photon-matter interactions need further advances in different areas as outlined below.

Since their discovery in early 1990s, dye sensitized solar cells (DSSCs) have been extensively investigated because of their potential in wide commercial applications for conversion of sunlight to electricity. The key interaction of light and matter in DSSCs is light induced interfacial charge transfer from transition metal complex dye sensitizers to semiconductor nanoparticles.101 108 Extensive […]