Plasmonic Effects in Organic Solar Cells
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Transcript of Plasmonic Effects in Organic Solar Cells
Plasmonic Effects in Organic Solar Cells
Wei E.I. Sha, Wallace C.H. Choy, Weng Cho Chew
Department of Electrical and Electronic EngineeringThe University of Hong Kong
Speaker: Wei E.I ShaEmail: [email protected]
PIERS 2012 in Kuala Lumpur, Malaysia
Plasmonic Effects in Organic Solar Cells (1)
organic solar cell
monocrystalline silicon solar cell amorphous/polycrystalline silicon solar cell
Advance of solar cell technology
Plasmonic Effects in Organic Solar Cells (2)
Thin-film organic solar cell
low-cost processingmechanically flexible large-area applicationenvironmentally friendlyХ low exciton diffusion length
Х low carrier mobility
Plasmonic Effects in Organic Solar Cells (3)
optical absorption
exciton diffusioncharge separation
charge collection
Working principle
Plasmonic Effects in Organic Solar Cells (4)
Why optical enhancement?
The thickness of the active layer must be smaller than the exciton diffusion length to avoid bulk recombination. As a result, the thin-film organic solar cell has poor photon absorption or harvesting. Plasmonic solar cell is one of emerging solar cell technologies to enhance the optical absorption.
Plasmonic Effects in Organic Solar Cells (5)
Lambert’s cosine law
finite-difference frequency-domain method (TE & TM)
PBCPBC
PML
PML
Au PEDOT:PSS Au
W.E.I. Sha, W.C.H. Choy, and W.C. Chew, Opt. Lett., 36(4), 478-480, 2011.
Small molecule organic solar cell
Plasmonic Effects in Organic Solar Cells (6)
X.H. Li, W.E.I. Sha, W.C.H. Choy, etc, J. Phys. Chem. C, 2012. In Press. doi: 10.1021/jp211237c
Plasmonic band edge boosted optical enhancement (theory and experiment)
Plasmonic Effects in Organic Solar Cells (7)
VIE-FFT method (BiCG-STAB)
enhancement factors
2 fold increase in total absorption!
Near-field Far-field
E
directional scatteringk
k k
W.E.I. Sha, W.C.H. Choy, Y.P. Chen, and W.C. Chew, Appl. Phys. Lett., 99(11), 113304, 2011.
active layerk
Bulk heterojunction polymer solar cell
Plasmonic Effects in Organic Solar Cells (8)
nanoparticles in spacer layer nanoparticles in active layer
Comparisons to experimental results
C.C.D. Wang, W.C.H. Choy, etc, J. Mater. Chem., 22, 1206-1211, 2011.D.D.S. Fung, L.F. Qiao, W.C.H. Choy, etc, J. Mater. Chem., 21, 16349-16356, 2011.
Plasmonic Effects in Organic Solar Cells (9)
good spectral overlap
Hybrid plasmonic system
λ 4 fold increase in total absorption!
W.E.I. Sha, W.C.H. Choy, and W.C. Chew, Opt. Express, 19(17), 15908-15918, 2011.
Plasmonic Effects in Organic Solar Cells (10)
Multiphysics modeling using unified finite difference method
W.E.I. Sha, W.C.H. Choy, Y.M. Wu, and W.C. Chew, Opt. Express, 20(3), 2572-2580, 2012.
Maxwell’s equation
generation rate
semiconductor equations
Plasmonic Effects in Organic Solar Cells (11)
Beyond optical absorption enhancement: facilitating hole collection!
Acknowledgement
Thanks for your attention!