Transient Absorption Spectroscopy
The transient absorption (TA) experiment allows quantitative characterization of time-dependent absorption of an optically excited sample. Two light pulses are required: femtosecond narrow-bandwidth pump pulse to excite the sample and delayed broad-bandwidth probe pulse to measure the changes in sample transmittance. The resulting difference absorption signal is measured as a function of probe wavelength and the temporal delay between the pump and probe pulses.
The TA spectrum is much more elaborate than, e.g., a steady-state absorption or fluorescence decay spectrum. It provides information not only on the excited states of the system but also on all the intermediate evolutionary transients and non-emissive states both on the ground and the excited states.
In HARPIA-TA, the TA experiment can be easily customized to get additional insight into the ultrafast dynamics of photoactive systems. For example, measuring transient reflection instead of absorption would provide more details on material surface photodynamics. Performing pump intensity-resolved absorption would help estimate the annihilation and saturation processes. Carrying TA experiments with different linear or circular pump pulse polarizations would allow obtaining molecular aggregation properties or molecular-level chirality-dependent spectra.
When the transient spectroscopy is not enough, the HARPIA-TA spectrometer can be expanded to perform time-resolved multi‑pulse and fluorescence spectroscopies using HARPIA-TB and HARPIA-TF modules, respectively.
- Transient absorption and reflection in bulk and microscopy
- Multi-pulse transient absorption and reflection
- Femtosecond fluorescence upconversion
- Femtosecond stimulated Raman scattering (FSRS)
- Picosecond-to-microsecond fluorescence TCSPC
- Intensity-dependent transient absorption and reflection
- Flash photolysis, Z-scan
- Market-leading sensitivity
- 330 nm – 24 μm spectral range
- Probe delay ranges from 2 to 8 ns
- Pump pulse energies down to nJ
- Cryostat and peristaltic pump support
- Delivery of an additional femtosecond or picosecond beam
- Polarization, intensity, and delay control
- Femtosecond stimulated Raman scattering (FSRS) support
- Z-scan support
- 100 fs – 20 ps tunable pulse duration
- 4 mJ maximum pulse energy
- 20 W maximum output power
- Single-shot – 1 MHz repetition rate
- Automated harmonic generators (up to 5th harmonic)
- 190 fs – 20 ps tunable pulse duration
- 2 mJ maximum pulse energy
- 80 W maximum output power
- Single-shot – 2 MHz repetition rate
- Air-cooled version
- 190 – 16000 nm tuning range
- Single-shot – 2 MHz repetition rate
- Up to 80 W pump power
- Up to 2 mJ pump pulse energy
- Completely automated
Atomic structure of a seed-sized gold nanoprism
Y. Song, Y. Li, M. Zhou, H. Li, T. Xu, C. Zhou, F. Ke, D. Huo, Y. Wan, J. Jie et al., Nature Communications 1 (13) (2022).
Charge Photogeneration and Recombination in Fluorine-Substituted Polymer Solar Cells
R. Hu, Y. Liu, J. Peng, J. Jiang, M. Qing, X. He, M. Huo, and W. Zhang, Frontiers in Chemistry 10 (2022).
Enhanced transfer efficiency of plasmonic hot-electron across Au/GaN interface by the piezo-phototronic effect
Y. Zhu, C. Deng, C. He, W. Zhao, Z. Chen, S. Li, K. Zhang, and X. Wang, Nano Energy 93, 106845 (2022).
Evidence and Governing Factors of the Radical-Ion Photoredox Catalysis
D. Y. Jeong, D. S. Lee, H. L. Lee, S. Nah, J. Y. Lee, E. J. Cho, and Y. You, ACS Catalysis, 6047-6059 (2022).
Exciton-Like and Mid-Gap Absorption Dynamics of PtS in Resonant and Transparent Regions
J. Huang, N. Dong, N. McEvoy, L. Wang, H. Wang, and J. Wang, Laser &$\mathsemicolon$ Photonics Reviews, 2100654 (2022).
Highly Efficient Quasi-2D Green Perovskite Light-Emitting Diodes with Bifunctional Amino Acid
C. Liu, Y. Liu, S. Wang, J. Liang, C. Wang, F. Yao, W. Ke, Q. Lin, T. Wang, C. Tao et al., Advanced Optical Materials, 2200276 (2022).
Insight into perovskite light-emitting diodes based on PVP buffer layer
N. Jiang, Z. Wang, J. Hu, M. Liu, W. Niu, R. Zhang, F. Huang, and D. Chen, 241, 118515 (2022).
Intrachain photophysics of a donor–acceptor copolymer
H. Nho, W. Park, B. Lee, S. Kim, C. Yang, and O. Kwon, Physical Chemistry Chemical Physics 4 (24), 1982-1992 (2022).
Photocatalytic overall water splitting under visible light enabled by a particulate conjugated polymer loaded with iridium
Y. Bai, C. Li, L. Liu, Y. Yamaguchi, B. Mounib, H. Yang, A. Gardner, M. Zwijnenburg, N. Browning, A. Cowan et al., (2022).
Photocycle of point defects in highly- and weakly-germanium doped silica revealed by transient absorption measurements with femtosecond tunable pump
V. D. Michele, A. Sciortino, M. Bouet, G. Bouwmans, S. Agnello, F. Messina, M. Cannas, A. Boukenter, E. Marin, S. Girard et al., Scientific Reports 1 (12) (2022).