This title appears in the Scientific Report :
2014
Please use the identifier:
http://dx.doi.org/10.1021/nl503249n in citations.
Nanoscale Observation of Waveguide Modes Enhancing the Efficiency of Solar Cells
Nanoscale Observation of Waveguide Modes Enhancing the Efficiency of Solar Cells
Nanophotonic light management concepts are on the way to advance photovoltaic technologies and accelerate their economical breakthrough. Most of these concepts make use of the coupling of incident sunlight to waveguide modes via nanophotonic structures such as photonic crystals, nanowires, or plasmo...
| Personal Name(s): | Paetzold, Ulrich W. (Corresponding Author) |
|---|---|
| Lehnen, Stephan / Bittkau, Karsten / Rau, Uwe / Carius, Reinhard | |
| Contributing Institute: |
Photovoltaik; IEK-5 |
| Published in: | Nano letters, 14 (2014) 11, S. 6599 - 6605 |
| Imprint: |
Washington, DC
ACS Publ.
2014
|
| PubMed ID: |
25350265 |
| DOI: |
10.1021/nl503249n |
| Document Type: |
Journal Article |
| Research Program: |
Thin Film Photovoltaics |
| Publikationsportal JuSER |
|
Nanophotonic light management concepts are on the way to advance photovoltaic technologies and accelerate their economical breakthrough. Most of these concepts make use of the coupling of incident sunlight to waveguide modes via nanophotonic structures such as photonic crystals, nanowires, or plasmonic gratings. Experimentally, light coupling to these modes was so far exclusively investigated with indirect and macroscopic methods, and thus, the nanoscale physics of light coupling and propagation of waveguide modes remain vague. In this contribution, we present a nanoscopic observation of light coupling to waveguide modes in a nanophotonic thin-film silicon solar cell. Making use of the subwavelength resolution of the scanning near-field optical microscopy, we resolve the electric field intensities of a propagating waveguide mode at the surface of a state-of-the-art nanophotonic thin-film solar cell. We identify the resonance condition for light coupling to this individual waveguide mode and associate it to a pronounced resonance in the external quantum efficiency that is found to increase significantly the power conversion efficiency of the device. We show that a maximum of the incident light couples to the investigated waveguide mode if the period of the electric field intensity of the waveguide mode matches the periodicity of the nanophotonic twodimensional grating. Our novel experimental approach establishes experimental access to the local analysis of light coupling to waveguide modes in a number of optoelectronic devices concerned with nanophotonic light-trapping as well as nanophotonic light emission. |