Researchers have been explained exciton dissociation with PL decay spectrum.
In the attached figure, plasmonic device exhibits faster decay compared to reference device. That means, plasmonic device shows short exciton life time.
It has been explained that this fast decay favors exciton dissociation. How it is related?
We know the exciton dissociation in polymer solar cell relies on an internal electric field. Here, plasmonic electric field intensity is higher. But, how the fast decay or short life time related to exciton dissociation?
Reference: ACS Nano, 2011, 5 (2), pp 959–967, DOI: 10.1021/nn102295p
it is very complex issue. the life time of exction depends on many factors. first, morphology of active materials. the metal will change the morphology. second, the exciton will quench at metal boundaries. third, the metal may affect the internal E-field distribution. four, some forster or Dexter energy transfer will be changed by metals. Thus, no one knows exactly what will happen in real devices.
if exciton is dissociated quickly or supports florescence quickly, the life time of exciton will be shorten.
@ wei
Thanks for your valuable response.
" if exciton is dissociated quickly or supports fluorescence quickly, the life time of exciton will be shorten".
How does exciton dissociation related to fluorescence?
One can envisage roughly three ways of exciton decay: radiative (that's fluorescence), nonradiative (enhanced by quenching near metal) and dissociation (you want that in solar cells). All of them would shorten exciton's lifetime to a finite value. Independently (mostly).
To understand the exciton-plasmon coupling mechanism visit the link
https://link.springer.com/content/pdf/10.1007%2Fs00339-013-8061-0.pdf
Thank you all for your valuable responses.
But I have not got clear idea.
My question was " How does exciton dissociation related to fluorescence?"
I think, you need to look into the gain and loss term expression in exciton diffusion equation which is second order differential equation. For detalis visit the link
https://link.springer.com/article/10.1007/s00339-013-8061-0
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