Imperial College London
Alternate

Dr Dimitrov

Faculty of Natural Sciences, Department of Chemistry

 
 
 
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Contact

 

s.dimitrov

 
 
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Location

 

CO62ChemistrySouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Collado:2016:10.1002/adfm.201604426,
author = {Collado, Fregoso E and Deledalle, F and Utzat, H and Tuladhar, PS and Dimitrov, S and Gillett, A and Tan, C and Zhang, W and McCulloch, I and Durrant, J},
doi = {10.1002/adfm.201604426},
journal = {Advanced Functional Materials},
title = {Photophysical study of DPPTT-T/PC70BM blends and solar devices as a function of fullerene loading: an insight into EQE limitations of DPP-based polymers},
url = {http://dx.doi.org/10.1002/adfm.201604426},
volume = {27},
year = {2016}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Diketopyrrolopyrrole  (DPP)-based  polymers  have  been  consistently  used  for  the fabrication  of  solar  cell  devices  and  transistors,  due  to the  existence  of  intermolecular short contacts,resulting in high electron and hole mobilities. However, they also often show limited external quantum efficiencies (EQEs). In this contribution we analyze the limitations on EQE by a combined study of exciton dissociation efficiency, charge separation and recombination kinetics in thin films and solar devices of a DPP-based donor polymer, DPPTT-T(thieno[3,2-b]thiophene-diketopyrrolopyrrolecopolymer)blended  with  varying  weight  fractions  of  the fullerene  acceptor  PC70BM.  From  the  correlations  between  photoluminescence  quenching (PLQ),  transient  absorption  studies  and EQEmeasurements,  we  concludethat  the  main limitation  of  photon-to-charge  conversion  in  DPPTT-T/PC70BM  devices  is  poor  exciton dissociation.  This  exciton  quenching  limit  is  related  to  the  low  affinity/miscibility  of  the materials, as confirmed by WAXDdiffraction and transmission electron microscopy data, but also  to  the  relatively  short  DPPTT-T  singlet  exciton  lifetime,possibly associated  with highnon-radiative losses.  A  further  strategy  to  improve  EQE  in  this  class  of  polymers  without sacrificing the good extractionproperties in optimized blends is therefore to limit those non-radiative decay processes.
AU  - Collado,Fregoso E
AU  - Deledalle,F
AU  - Utzat,H
AU  - Tuladhar,PS
AU  - Dimitrov,S
AU  - Gillett,A
AU  - Tan,C
AU  - Zhang,W
AU  - McCulloch,I
AU  - Durrant,J
DO  - 10.1002/adfm.201604426
PY  - 2016///
SN  - 1616-3028
TI  - Photophysical study of DPPTT-T/PC70BM blends and solar devices as a function of fullerene loading: an insight into EQE limitations of DPP-based polymers
T2  - Advanced Functional Materials
UR  - http://dx.doi.org/10.1002/adfm.201604426
UR  - http://hdl.handle.net/10044/1/42194
VL  - 27
ER  -
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