Imperial College London
Alternate

Dr Pabitra Shakya Tuladhar

Faculty of Natural Sciences, Department of Chemistry

Research Technician in Organic Electronics
 
 
 
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Contact

 

+44 (0)20 7594 5710p.shakya

 
 
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Location

 

G22Molecular Sciences Research HubWhite City Campus

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Summary

 

Publications

Citation

BibTex format

@article{Utzat:2017:10.1021/acs.jpcc.7b02898,
author = {Utzat, H and Dimitroy, SD and Wheeler, S and Collado-Fregoso, E and Tuladhar, PS and Schroeder, BC and McCulloch, I and Durrant, JR},
doi = {10.1021/acs.jpcc.7b02898},
journal = {JOURNAL OF PHYSICAL CHEMISTRY C},
pages = {9790--9801},
title = {Charge-Separation in Intermixed Polymer:PC70BM Photovoltaic Blends: Correlating Structural and Photophysical Length Scales as a Function of Blend Composition},
url = {http://dx.doi.org/10.1021/acs.jpcc.7b02898},
volume = {121},
year = {2017}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - A key challenge in achieving control over photocurrent generation by bulk-heterojunction organic solar cells is understanding how the morphology of the active layer impacts charge separation and in particular the separation dynamics within molecularly intermixed donor–acceptor domains versus the dynamics between phase-segregated domains. This paper addresses this issue by studying blends and devices of the amorphous silicon–indacenodithiophene polymer SiIDT-DTBT and the acceptor PC70BM. By changing the blend composition, we modulate the size and density of the pure and intermixed domains on the nanometer length scale. Laser spectroscopic studies show that these changes in morphology correlate quantitatively with the changes in charge separation dynamics on the nanosecond time scale and with device photocurrent densities. At low fullerene compositions, where only a single, molecularly intermixed polymer–fullerene phase is observed, photoexcitation results in a ∼ 30% charge loss from geminate polaron pair recombination, which is further studied via light intensity experiments showing that the radius of the polaron pairs in the intermixed phase is 3–5 nm. At high fullerene compositions (≥67%), where the intermixed domains are 1–3 nm and the pure fullerene phases reach ∼4 nm, the geminate recombination is suppressed by the reduction of the intermixed phase, making the fullerene domains accessible for electron escape.
AU  - Utzat,H
AU  - Dimitroy,SD
AU  - Wheeler,S
AU  - Collado-Fregoso,E
AU  - Tuladhar,PS
AU  - Schroeder,BC
AU  - McCulloch,I
AU  - Durrant,JR
DO  - 10.1021/acs.jpcc.7b02898
EP  - 9801
PY  - 2017///
SN  - 1932-7447
SP  - 9790
TI  - Charge-Separation in Intermixed Polymer:PC70BM Photovoltaic Blends: Correlating Structural and Photophysical Length Scales as a Function of Blend Composition
T2  - JOURNAL OF PHYSICAL CHEMISTRY C
UR  - http://dx.doi.org/10.1021/acs.jpcc.7b02898
UR  - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000401402100017&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR  - http://hdl.handle.net/10044/1/49011
VL  - 121
ER  -
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