scholarly journals Transient Absorption and Raman Studies on Exciplex Formation Dynamics of Photoexcited Cu(II)(TMpy-P4) With Synthetic Polynucleotide

1999 ◽  
Vol 19 (1-4) ◽  
pp. 299-303 ◽  
Author(s):  
Sae Chae Jeoung ◽  
Hyo Soon Eom ◽  
Dongho Kim
Keyword(s):  
Time Constant ◽  
Decay Time ◽  
Strong Correlation ◽  
Transient Absorption ◽  
Spectroscopic Methods ◽  
Raman Spectroscopic ◽  
Exciplex Formation ◽  
Femtosecond Transient Absorption ◽  
Formation Dynamics ◽  
Synthetic Polynucleotide

Exciplex formation dynamics of photoexcited copper(II) tetrakis (4-N-methylpyridyl) porphyrin (Cu(II)(TMpy-P4)) with added poly(dA-dT)2 and poly(dG-dC)2 has been investigated by using femtosecond transient absorption and nanosecond and picosecond transient Raman spectroscopic methods. It was observed that the decay time constant of the exciplex is strongly dependent on the polynucleotide and has a strong correlation with the appearance of new transient Raman bands.

scholarly journals Direct Observation of S2–S1 Internal Conversion in Pyrene by Femtosecond Transient Absorption

1999 ◽  
Vol 19 (1-4) ◽  
pp. 375-379 ◽  
Author(s):  
Frederik V. R. Neuwahl ◽  
Paolo Foggi
Keyword(s):  
Time Constant ◽  
Absorption Spectroscopy ◽  
Direct Observation ◽  
Internal Conversion ◽  
Transient Absorption ◽  
Conversion Process ◽  
Transient Absorption Spectroscopy ◽  
Kinetic Measurements ◽  
State Population ◽  
Femtosecond Transient Absorption

UV pulses of 100 fs at 340 nm are utilised to excite pyrene to the vibrationally cold S2 state. Population and depopulation processes occurring in the S2 state are investigated by transient absorption spectroscopy with a white continuum probe. In the first 400 fs after excitation it is possible to measure the growth and disappearance of a band at 585 nm which is assigned to the S14←S2 transition. As a consequence of the internal conversion process from S2 to S1 state, the disappearance of the 585 nm band and the growth of the transient spectrum due to Sn←S1 transitions can be observed. Kinetic measurements of the S2 decay and S1 growing signals provide an estimate of the rate of internal conversion which occurs with a time constant of 150±50 fs.

scholarly journals Femtosecond Transient Absorption Studies of Two Novel Energetic Tetrazole Derivatives

2021 ◽  
pp. 100016
Author(s):  
Naga Krishnakanth Katturi ◽  
Chinmoy Biswas ◽  
Nagarjuna Kommu ◽  
Sai Santosh Kumar Raavi ◽  
Venugopal Rao Soma
Keyword(s):  
Transient Absorption ◽  
Femtosecond Transient Absorption ◽  
Absorption Studies ◽  
Tetrazole Derivatives

scholarly journals Measurement of Decay Time Constant of Shielding Current in ITER-TF Joint Samples

2021 ◽  
Vol 1857 (1) ◽  
pp. 012013
Author(s):  
S Imagawa ◽  
H Kajitani ◽  
T Obana ◽  
S Takada ◽  
S Hamaguchi ◽  
...  
Keyword(s):  
Time Constant ◽  
Decay Time ◽  
Decay Time Constant

scholarly journals Ultrafast nonequilibrium dynamic process of separate electron and hole during exciton formation in few-layer tungsten disulfide

2021 ◽  
Author(s):  
Junjie Chen ◽  
Sen Guo ◽  
Dabin Lin ◽  
Zhaogang Nie ◽  
Chung-Che Huang ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Dynamic Process ◽  
Formation Process ◽  
Transient Absorption ◽  
Tungsten Disulfide ◽  
Transient Absorption Spectroscopy ◽  
Femtosecond Transient Absorption ◽  
Nonequilibrium Dynamic ◽  
Femtosecond Transient Absorption Spectroscopy ◽  
Separate Electron

Femtosecond transient absorption spectroscopy has been employed to unravel separate initial nonequilibrium dynamic process of photo-injected electrons and holes during the formation process of the lowest excitons at the K-valley...

scholarly journals SnSe Nanosheets: From Facile Synthesis to Applications in Broadband Photodetections

Nanomaterials ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 49
Author(s):  
Xiangyang Li ◽  
Zongpeng Song ◽  
Huancheng Zhao ◽  
Wenfei Zhang ◽  
Zhenhua Sun ◽  
...  
Keyword(s):  
Transient Absorption ◽  
Ultrafast Optics ◽  
Light Response ◽  
Transient Absorption Spectroscopy ◽  
Monolayer Graphene ◽  
Proof Of Concept ◽  
Facile Synthesis ◽  
Femtosecond Transient Absorption ◽  
Potential Applications ◽  
Promising Area

In recent years, using two-dimensional (2D) materials to realize broadband photodetection has become a promising area in optoelectronic devices. Here, we successfully synthesized SnSe nanosheets (NSs) by a facile tip ultra-sonication method in water-ethanol solvent which was eco-friendly. The carrier dynamics of SnSe NSs was systematically investigated via a femtosecond transient absorption spectroscopy in the visible wavelength regime and three decay components were clarified with delay time of τ1 = 0.77 ps, τ2 = 8.3 ps, and τ3 = 316.5 ps, respectively, indicating their potential applications in ultrafast optics and optoelectronics. As a proof-of-concept, the photodetectors, which integrated SnSe NSs with monolayer graphene, show high photoresponsivities and excellent response speeds for different incident lasers. The maximum photo-responsivities for 405, 532, and 785 nm were 1.75 × 104 A/W, 4.63 × 103 A/W, and 1.52 × 103 A/W, respectively. The photoresponse times were ~22.6 ms, 11.6 ms, and 9.7 ms. This behavior was due to the broadband light response of SnSe NSs and fast transportation of photocarriers between the monolayer graphene and SnSe NSs.

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