Femtosecond Pump−Probe Transient Absorption Study of the Photolysis of [Cp‘Mo(CO)3]2(Cp‘ = η5-C5H4CH3):  Role of Translational and Rotational Diffusion in the Radical Cage Effect

2007 ◽  
Vol 111 (25) ◽  
pp. 5353-5360 ◽  
Author(s):  
Alan B. Oelkers ◽  
Lawrence F. Scatena ◽  
David R. Tyler
Keyword(s):  
Transient Absorption ◽  
Rotational Diffusion ◽  
Cage Effect ◽  
Absorption Study ◽  
Pump Probe ◽  
Translational And Rotational Diffusion

scholarly journals The role of spin in the degradation of organic photovoltaics

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ivan Ramirez ◽  
Alberto Privitera ◽  
Safakath Karuthedath ◽  
Anna Jungbluth ◽  
Johannes Benduhn ◽  
...  
Keyword(s):  
Transient Absorption ◽  
Bulk Heterojunction ◽  
Critical Factor ◽  
Model Systems ◽  
Transient Absorption Spectroscopy ◽  
Triplet States ◽  
Paramagnetic Resonance ◽  
Time Resolved ◽  
A Charge

AbstractStability is now a critical factor in the commercialization of organic photovoltaic (OPV) devices. Both extrinsic stability to oxygen and water and intrinsic stability to light and heat in inert conditions must be achieved. Triplet states are known to be problematic in both cases, leading to singlet oxygen production or fullerene dimerization. The latter is thought to proceed from unquenched singlet excitons that have undergone intersystem crossing (ISC). Instead, we show that in bulk heterojunction (BHJ) solar cells the photo-degradation of C60 via photo-oligomerization occurs primarily via back-hole transfer (BHT) from a charge-transfer state to a C60 excited triplet state. We demonstrate this to be the principal pathway from a combination of steady-state optoelectronic measurements, time-resolved electron paramagnetic resonance, and temperature-dependent transient absorption spectroscopy on model systems. BHT is a much more serious concern than ISC because it cannot be mitigated by improved exciton quenching, obtained for example by a finer BHJ morphology. As BHT is not specific to fullerenes, our results suggest that the role of electron and hole back transfer in the degradation of BHJs should also be carefully considered when designing stable OPV devices.

scholarly journals Deciphering the role of quantum dot size in the ultrafast charge carrier dynamics at the perovskite–quantum dot interface

2020 ◽  
Vol 8 (42) ◽  
pp. 14834-14844
Author(s):  
Piotr Piatkowski ◽  
Sofia Masi ◽  
Pavel Galar ◽  
Mario Gutiérrez ◽  
Thi Tuyen Ngo ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Charge Carrier ◽  
Rate Constants ◽  
Transient Absorption ◽  
Carrier Dynamics ◽  
Carrier Transfer ◽  
Charge Carrier Dynamics ◽  
Conduction Bands

Charge-carrier transfer (CT) from the perovskite host to PbS QDs were studied using fs-transient absorption and THz techniques. The CT rate constants increase with the size of QDs due to a change in the position of valence and conduction bands in PbS QDs.

scholarly journals Nonequilibrium electron dynamics in pump-probe spectroscopy: Role of excited phonon populations

2018 ◽  
Vol 98 (24) ◽  
Author(s):  
O. Abdurazakov ◽  
D. Nevola ◽  
A. Rustagi ◽  
J. K. Freericks ◽  
D. B. Dougherty ◽  
...  
Keyword(s):  
Electron Dynamics ◽  
Nonequilibrium Electron ◽  
Pump Probe ◽  
Probe Spectroscopy
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