TY - JOUR
T1 - Exciton dissociation at nanostructured donor-acceptor interfaces
AU - Rumbles, Garry
AU - Kopdakis, Nikos
AU - Ferguson, Andrew
AU - Coffey, David
AU - Holt, Josh
AU - Blackburn, Jeffrey
PY - 2011/12/1
Y1 - 2011/12/1
N2 - Photovoltaic solar cells based on organic systems are emerging as a viable technology platform, with current devices exhibiting good performance and durability. Common to almost all of these new devices is a nanostructured interface that comprises a electron donor system, often a conjugated polymer such as poly (3-hexylthiophene), and more often than not, C 60 as an electron acceptor. A unique and essential feature of these interfaces is the ability to efficiently dissociate the photo-generated excitons into free carriers and, more importantly, to very effectively inhibit the reverse, recombination process. A uniform consensus on why this happens has yet to emerge and it is therefore a topic of great interest. Although they are considered to be a viable technology, solar cell power conversion efficiencies have only just exceeded 8%, and while this value is impressive, a further factor of two, at minimum, is needed. Incremental improvements in device performance cannot achieve this goal, and it requires a more fundamental, basic research to be focused on the problem. It is this type of approach that motivates this presentation. The talk will focus on the use of time-resolved microwave conductivity, using pulsed laser excitation, as a tool for probing both the production and loss of free carriers that result from exciton dissociation. Two systems will be examined: (i) the use of single-wall carbon nanotubes (SWNTs) instead of PCBM as the electron acceptor when dispersed in a conjugated polymer film, and (ii) the dissociation of excitons generated directly in PCBM when dispersed in a range of hole-accepting polymers.
AB - Photovoltaic solar cells based on organic systems are emerging as a viable technology platform, with current devices exhibiting good performance and durability. Common to almost all of these new devices is a nanostructured interface that comprises a electron donor system, often a conjugated polymer such as poly (3-hexylthiophene), and more often than not, C 60 as an electron acceptor. A unique and essential feature of these interfaces is the ability to efficiently dissociate the photo-generated excitons into free carriers and, more importantly, to very effectively inhibit the reverse, recombination process. A uniform consensus on why this happens has yet to emerge and it is therefore a topic of great interest. Although they are considered to be a viable technology, solar cell power conversion efficiencies have only just exceeded 8%, and while this value is impressive, a further factor of two, at minimum, is needed. Incremental improvements in device performance cannot achieve this goal, and it requires a more fundamental, basic research to be focused on the problem. It is this type of approach that motivates this presentation. The talk will focus on the use of time-resolved microwave conductivity, using pulsed laser excitation, as a tool for probing both the production and loss of free carriers that result from exciton dissociation. Two systems will be examined: (i) the use of single-wall carbon nanotubes (SWNTs) instead of PCBM as the electron acceptor when dispersed in a conjugated polymer film, and (ii) the dissociation of excitons generated directly in PCBM when dispersed in a range of hole-accepting polymers.
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M3 - Conference article
AN - SCOPUS:84861085231
JO - ACS National Meeting Book of Abstracts
JF - ACS National Meeting Book of Abstracts
SN - 0065-7727
T2 - 242nd ACS National Meeting and Exposition
Y2 - 28 August 2011 through 1 September 2011
ER -