| Autor: |
Rudenko, Valentyn, Brodyn, Mykhailo, Liakhovetskyi, Volodymyr, Styopkin, Viktor, Brodin, Alexandr |
| Předmět: |
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| Zdroj: |
Applied Nanoscience; Oct2023, Vol. 13 Issue 10, p6859-6863, 5p |
| Abstrakt: |
Transient absorption in thin PdO films in the spectral range of the resonant absorption band at 2.55 eV was investigated by the femtosecond time-resolved pump-probe spectroscopy under 800 nm (1.55 eV) and 400 nm (3.1 eV) excitation. It was found that the induced changes of absorption in the central and wing regions of the 2.55 eV band have different signs, which signifies an induced change in the shape of the absorption band. The relaxation of these changes takes place in two stages: fast, with almost the same relaxation time of τ1 = 3 ps for 800 nm and 400 nm excitation, and slow τ2 = 2 ns. The peculiarities of the induced changes of absorption reflect changes in the shape and width of the long-wavelength part of the 2.55 eV band under intense excitation. Specifically, with 800 nm excitation, the width somewhat increases, whereas under 400 nm irradiation, the width more significantly decreases. The changes under 800 nm excitation may be due to inter-band transitions from deep valence band states into empty hole states at the top of the band. Under 400 nm (3.10 eV) excitation, however, there occur inter-band transitions from the valence band into energy states above those of the 2.55 eV band and with different selection rules, which determines the above-mentioned changes of the 2.55 eV band. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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