Intersublevel optical transitions in InAs nanocrystals probed by photoinduced absorption spectroscopy: The role of thermal activation

2004 ◽  
Vol 69 (7) ◽  
Author(s):  
D. Krapf ◽  
S.-H. Kan ◽  
U. Banin ◽  
O. Millo ◽  
A. Sa’ar
Keyword(s):  
Absorption Spectroscopy ◽  
Thermal Activation ◽  
Optical Transitions ◽  
Photoinduced Absorption

Photoinduced Absorption Spectroscopy of Poly-3-Alkylthiophenes

1992 ◽  
Vol 247 ◽  
Author(s):  
C. Botta ◽  
S. Luzzati ◽  
A. Bolognesi ◽  
R. Tubino ◽  
A. Borghesi
Keyword(s):  
Absorption Spectroscopy ◽  
Near Infrared ◽  
Laser Intensity ◽  
Electronic States ◽  
Chain Mechanism ◽  
Photoinduced Absorption ◽  
Polymer Aggregates ◽  
Cast Films ◽  
Solution Cast

ABSTRACTWe report a study of the near infrared photoinduced absorption of a series of poly -3-decylthiophene with different supermolecular organization as solution cast films, good solvent and aggregated bad solvent solutions.Photoinduced subgap electronic states are detected both in the solid and in solutions independently from the presence of polymer aggregates. The study of the photoinduced activity Δ/T on the laser intensity I indicate a I0.6 dependence for the films and a I0.95 dependence for the solutions. This is the evidence that the photoinduced states are generated in the solid via an inter-chain mechanism while in the solution via an intra-chain mechanism.A possible role of the solvent into the photoexcitation pathway is discussed.

scholarly journals Probing P25 TiO2 Photocatalysis Using Photoinduced Absorption Spectroscopy (PIAS)

2021 ◽  
Author(s):  
Andrew Mills ◽  
Christopher O'Rourke
Keyword(s):  
Absorption Spectroscopy ◽  
Photoinduced Absorption ◽  
Tio2 Photocatalysis ◽  
Mesoporous Film ◽  
First Time ◽  
Film Form

Photoinduced absorption spectroscopy, PIAS, is used for the first time to probe the kinetics exhibited by the most commonly employed powder photocatalyst, P25 TiO2, in mesoporous film form, in the...

scholarly journals Iron Speciation in Different Saharan Dust Advections and Effect of the Procedural Blank on the Results From X-ray Absorption Spectroscopy and Selective Leaching Experiments

Atmosphere ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 735
Author(s):  
Chiara Petroselli ◽  
Beatrice Moroni ◽  
Stefano Crocchianti ◽  
Roberta Selvaggi ◽  
Francesco Soggia ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Saharan Dust ◽  
Residual Fraction ◽  
Selective Leaching ◽  
Iron Speciation ◽  
X Ray ◽  
Fe Speciation ◽  
Leaching Experiments ◽  
X Ray Absorption

In this work, we applied X-ray Absorption Spectroscopy (XAS) and selective leaching experiments for investigating iron speciation in different dust advections collected on different unwashed quartz fiber filters. XAS analysis evidenced a predominance of Fe(III) in 6-fold coordination for Saharan dust and a trend towards Fe(II) and 4-fold coordination in the order: Saharan dust, mixed Saharan, and non-Saharan aerosol samples. The role of the sampling substrate was evaluated explicitly, including in the analysis a set of blank filters. We were able to pinpoint the possible contribution to the overall XAS spectrum of the residual Fe on quartz as the concentration decrease towards the blank value. In particular, the filter substrate showed a negligible effect on the structural trend mentioned above. Furthermore, selective leaching experiments evidenced a predominance of the residual fraction on Fe speciation and indicated the lowest Fe concentrations for which the blank contribution is <20% are 1 μ g for the first three steps of the procedure (releasing the acid-labile, reducible and oxidizable phases, respectively) and 10 μ g for the last step (dissolving the insoluble residuals).

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