Transient absorption studies of vibrational relaxation and photophysics of Prussian blue and ruthenium purple nanoparticles

2011 ◽  
Vol 134 (12) ◽  
pp. 124510 ◽  
Author(s):  
D. Weidinger ◽  
D. J. Brown ◽  
J. C. Owrutsky
Keyword(s):  
Prussian Blue ◽  
Vibrational Relaxation ◽  
Transient Absorption ◽  
Absorption Studies

scholarly journals Femtosecond Transient Absorption Studies of Simple Polyenes in Solution

1999 ◽  
Vol 19 (1-4) ◽  
pp. 371-374
Author(s):  
Kaoru Ohta ◽  
Yukito Naitoh ◽  
Keisuke Tominaga ◽  
Noboru Hirota ◽  
Keitaro Yoshihara
Keyword(s):  
Ground State ◽  
Vibrational Relaxation ◽  
Internal Conversion ◽  
Transient Absorption ◽  
Visible Region ◽  
Single Bond ◽  
Femtosecond Transient Absorption ◽  
Absorption Studies ◽  
Bond Proceeds ◽  
Subnanosecond Time

We have conducted femtosecond transient absorption experiments on the excited-state dynamics of trans- and cis-hexatriene (HT) in solution. The transient absorption in the visible region decays with the time constant of about 500 fs, indicating that the internal conversion (IC) to the ground state occurs quite efficiently. The bleach recovery signal contains several time constants. The vibrational relaxation in the ground state occurs in 10–20ps and the slow relaxation process, which may be due to the conformational change around C—C single bond, proceeds in a subnanosecond time scale.

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

Covalent decoration onto the outer walls of double walled carbon nanotubes with perylenediimides

2015 ◽  
Vol 3 (19) ◽  
pp. 4960-4969 ◽  
Author(s):  
Myriam Barrejón ◽  
Sara Pla ◽  
Isadora Berlanga ◽  
María J. Gómez-Escalonilla ◽  
Luis Martín-Gomis ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Charge Separation ◽  
Transient Absorption ◽  
Femtosecond Transient Absorption ◽  
Covalently Bonded ◽  
Absorption Studies ◽  
Double Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Three new covalently bonded DWCNT–PDIs have been synthesized and characterized, showing exclusively functionalization of the outer walls leaving the inner walls intact. Femtosecond transient absorption studies were performed to seek evidence of charge separation in these hybrids.

scholarly journals Ultrafast Exciton Dynamics in Two Dimensional Covalent Organic Frameworks Reveals Size Dependence to Exciton Diffusion

2020 ◽  
Author(s):  
Nathan C. Flanders ◽  
Matthew S. Kirschner ◽  
Pyosang Kim ◽  
Thomas Fauvell ◽  
Austin Evans ◽  
...  
Keyword(s):  
High Performance ◽  
Transient Absorption ◽  
Domain Size ◽  
Spectroscopic Techniques ◽  
Two Dimensional ◽  
Exciton Dynamics ◽  
Singlet Exciton ◽  
Exciton Diffusion ◽  
Absorption Studies ◽  
Exciton Annihilation

<p>Large singlet exciton diffusion lengths are a hallmark of high performance in organic based devices such as photovoltaics, chemical sensors, and photodetectors. In this study, exciton dynamics of a two-dimensional covalent organic framework, COF- 5, is investigated using ultrafast spectroscopic techniques. Following photoexcitation, the COF-5 exciton decays via three pathways: 1) excimer formation (4 ± 2 ps), 2) excimer relaxation (160 ± 40 ps), and 3) excimer decay (>3 ns). Excitation fluence-dependent transient absorption studies suggest that COF-5 has a relatively large diffusion coefficient (0.08 cm2/s). Furthermore, exciton-exciton annihilation processes are characterized as a function of COF-5 crystallite domain size in four different samples, which reveal domain- size dependent exciton diffusion kinetics. These results reveal that exciton diffusion in COF-5 is constrained by its crystalline domain size. These insights indicate the outstanding promise of delocalized excitonic processes available in 2D COFs, which motivate their continued design and implementation into optoelectronic devices. </p>

Transient Absorption Studies and Numerical Modeling of Iodine Photoreduction by Nanocrystalline TiO2Films

2005 ◽  
Vol 109 (1) ◽  
pp. 142-150 ◽  
Author(s):  
Alex N. M. Green ◽  
Rosemary E. Chandler ◽  
Saif A. Haque ◽  
Jenny Nelson ◽  
James R. Durrant
Keyword(s):  
Numerical Modeling ◽  
Transient Absorption ◽  
Absorption Studies

scholarly journals Subpicosecond transient absorption studies of the photocycloreversion of an aromatic endoperoxide

1990 ◽  
Vol 94 (13) ◽  
pp. 5252-5255 ◽  
Author(s):  
N. P. Ernsting ◽  
R. Schmidt ◽  
H. D. Brauer
Keyword(s):  
Transient Absorption ◽  
Absorption Studies

scholarly journals Ultrafast Charge Generation Enhancement in Nanoscale Polymer Solar Cells with DIO Additive

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2174
Author(s):  
Tongchao Shi ◽  
Zeyu Zhang ◽  
Xia Guo ◽  
Zhengzheng Liu ◽  
Chunwei Wang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Vibrational Relaxation ◽  
Transient Absorption ◽  
Polymer Solar Cells ◽  
Acid Methyl Ester ◽  
Free Charge ◽  
Exciton Dissociation ◽  
Charge Generation ◽  
Carrier Generation ◽  
Acid Methyl

We study the ultrafast photoexcitation dynamics in PBDTTT-C-T (P51, poly(4,8-bis(5-(2-ethylhexyl)-thiophene-2-yl)-benzo[1,2-b:4,5-b′]dithiophene-alt-alkylcarbonyl-thieno[3,4-b]thiophene)) film (~100 nm thickness) and PBDTTT-C-T:PC71BM (P51:PC71BM, phenyl-C71-butyric-acid-methyl ester) nanostructured blend (∼100 nm thickness) with/without DIO(1,8-diiodooctane) additives with sub-10 fs transient absorption (TA). It is revealed that hot-exciton dissociation and vibrational relaxation could occur in P51 with a lifetime of ~160 fs and was hardly affected by DIO. However, the introduction of DIO in P51 brings a longer lifetime of polaron pairs, which could make a contribution to photocarrier generation. In P51:PC71BM nanostructured blends, DIO could promote the Charge Transfer (CT) excitons and free charges generation with a ~5% increasement in ~100 fs. Moreover, the dissociation of CT excitons is faster with DIO, showing a ~5% growth within 1 ps. The promotion of CT excitons and free charge generation by DIO additive is closely related with active layer nanomorphology, accounting for Jsc enhancement. These results reveal the effect of DIO on carrier generation and separation, providing an effective route to improve the efficiency of nanoscale polymer solar cells.

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