Integrated optical and electrical modeling of plasmon-enhanced thin film photovoltaics: A case-study on organic devices

Journal Article · Sun Sep 21 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4896167· OSTI ID:22306230

Rourke, Devin ^[1]; Ahn, Sungmo ^[2]; Nardes, Alexandre M.; Lagemaat, Jao van de; Kopidakis, Nikos ^[3]; Park, Wounjhang ^[2]

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1. Department of Physics, University of Colorado, Boulder, Colorado 80309-0390 (United States)
2. Department of Electrical, Computer, and Energy Engineering, University of Colorado, Boulder, Colorado 80309-0425 (United States)
3. National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401 (United States)

The nanoscale light control for absorption enhancement of organic photovoltaic (OPV) devices inevitably produces strongly non-uniform optical fields. These non-uniformities due to the localized optical modes are a primary route toward absorption enhancement in OPV devices. Therefore, a rigorous modeling tool taking into account the spatial distribution of optical field and carrier generation is necessary. Presented here is a comprehensive numerical model to describe the coupled optical and electrical behavior of plasmon-enhanced polymer:fullerene bulk heterojunction (BHJ) solar cells. In this model, a position-dependent electron-hole pair generation rate that could become highly non-uniform due to photonic nanostructures is directly calculated from the optical simulations. By considering the absorption and plasmonic properties of nanophotonic gratings included in two different popular device architectures, and applying the Poisson, current continuity, and drift/diffusion equations, the model predicts quantum efficiency, short-circuit current density, and desired carrier mobility ratios for bulk heterojunction devices incorporating nanostructures for light management. In particular, the model predicts a significant degradation of device performance when the carrier species with lower mobility are generated far from the collecting electrode. Consequently, an inverted device architecture is preferred for materials with low hole mobility. This is especially true for devices that include plasmonic nanostructures. Additionally, due to the incorporation of a plasmonic nanostructure, we use simulations to theoretically predict absorption band broadening of a BHJ into energies below the band gap, resulting in a 4.8% increase in generated photocurrent.

• OSTI ID: 22306230
• Journal Information: Journal of Applied Physics, Vol. 116, Issue 11; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION
CARRIER MOBILITY
CURRENT DENSITY
DIFFUSION EQUATIONS
ELECTRICAL PROPERTIES
ELECTRODES
FULLERENES
HETEROJUNCTIONS
HOLE MOBILITY
NANOSTRUCTURES
OPTICAL MODES
OPTICAL PROPERTIES
PHOTOVOLTAIC EFFECT
POLYMERS
QUANTUM EFFICIENCY
SIMULATION
SOLAR CELLS
SPATIAL DISTRIBUTION
THIN FILMS
VISIBLE RADIATION