APS beamline 25-ID-E provides time-resolved X-ray spectroscopy and scattering techniques to investigate multiple time-scale and length-scale electronic and structural dynamics underlying photochemical and photophysical processes in chemistry, physics, and materials science. These TR techniques developed in laser pump x-ray probe scheme utilize a laser pulse to excite sample systems and then interrogate them with stroboscopic x-ray pulse snapshots, spanning the time scale from 200-300 ps (time resolution) to 1 ms at the atomic level.  The 25-ID beamline is shared with the APS Spectroscopy group.

Supported techniques and their applications:

• Time-resolved x-ray absorption spectroscopy (TR-XAS), including time-resolved x-ray absorption near edge structure (TR-XANES) and time-resolved extended x-ray absorption fine structure (TR-EXAFS), to study oxidation states, unoccupied electronic states, number and species of neighbor atoms, and local geometric structure
• Time-resolved x-ray emission spectroscopy (TR-XES), to study spin states, occupied electronic states, oxidation states, and chemical bonding
• Time-resolved scattering (TR-XS) including diffraction, to study crystalline strain, deformations, phase transitions, and global molecular structural changes

The x-ray source is a 2.7-mm undulator.  The Axilon double-crystal monochromator allows a choice between Si(111) with an energy range of 4 to 40 keV and bandpass of 10^-4, or a broadband multilayer with a bandpass of 10^-2.

A range of excitation lasers are available (some operated in conjunction with the AMO group of Argonne's CSE division), including Ti:sapphire, Duetto, Pharos, and Satsuma.  The Ti:sapphire and Pharos also have OPAs as options.

Sample environments can be switched for solutions (e.g., molecules, metal complexes), suspensions (e.g., NCs, MOFs), and thin films (e.g., perovskite films, 2D material layers)

• Bright and durable scintillation from colloidal quantum shells, Burak Guzelturk, Benjamin T. Diroll, James P. Cassidy, Dulanjan Harankahage, Muchuan Hua, Xiao-Min Lin, Vasudevan Iyer, Richard D. Schaller, Benjamin J. Lawrie, Mikhail Zamkov,  Nature Communications 15, 4274 (2024).
• Long-Lived and Bright Biexcitons in Quantum Dots with Parabolic Band Potentials, Benjamin T. Diroll, Muchuan Hua, Burak Guzelturk, Marcell Pálmai, Kyle Tomczak,  Nano Letters 23, 11975 (2023).