| AVS 57th International Symposium & Exhibition | |
| Nanometer-scale Science and Technology | Wednesday Sessions |
| Session NS+EM+EN-WeA |
| Session: | Photonic and Plasmonic Materials and Devices |
| Presenter: | M. Creatore, Eindhoven University of Technology, Netherlands |
| Authors: | M. Creatore, Eindhoven University of Technology, Netherlands H. Takeke Beyene, Eindhoven University of Technology, Netherlands M. Ponomarev, Eindhoven University of Technology, Netherlands M.C.M. van de Sanden, Eindhoven University of Technology, Netherlands |
| Correspondent: | Click to Email |
The combination of (noble) metal nanoparticles (NPs) with dielectrics is an on-going research subject, due to the generated surface plasmon reasonance (SPR) effect, relevant in several technological applications such as color filters, optical switching devices and sensors, to name a few.
In this contribution, we report on the tunability and control of the surface plasmon resonance behaviour through the engineering of metal NP/dielectric interfaces for two applications, i.e. thickness- and viewing angle- independent red- coloured decorative coatings and light trapping enhancement in silicon- based tandem thin film solar cells. Both studies have been carried out by making use of a vacuum chamber where plasma- enhanced chemical vapour deposition for the dielectric layer and magnetron sputtering for the metal NP deposition are combined.
Multilayer structures composed of gold NPs sandwiched between SiO2 layers represent a valid solution for the independent control of NP size and density: while a constant NP size guarantees a narrow surface plasmon frequency, an increased NP density leads to an enhancement in the absorption [1]. A multi-diagnostic approach consisting of spectroscopic ellipsometry, transmission electron microscopy and Rutherford backscattering analysis has allowed the characterization of the deposited coatings: gold NPs (diameter 10-15 nm) with a surface area coverage of 26% and sandwiched between 40 nm- thick SiO2 layers, exhibit a red colour, whereas the color intensity (i.e. from cool to warm deep red) increases with the layer number, i.e. NP density.
While in this first application the main mechanism contributing to extinction is absorption, for an efficient sun light management/ trapping within a solar cell, scattering plays a dominant role. In particular, for amorphous (a-Si:H)/microcrystalline (μc-Si:H) silicon tandem solar cells a promising approach consists in the incorporation of an intermediate layer (e.g. ZnO) sandwiched between the top a-Si:H and the bottom μc-Si:H cell, able to efficiently scatter photons of a specific frequency range back to the top cell or forward to the bottom cell. In this respect, copper NPs (30-150 nm diameter) when coupled to ZnO layers, are responsible for the generation of a plasmon peak at 700 nm, which shifts towards higher wavelengths with an increase in NP size, therefore showing its potential towards low energy photon forward scattering into the bottom μc-Si:H cell.
[1] H. T. Beyene, F.D. Tichelaar, P. Peeters, I. Kolev, M.C.M. van de Sanden, M. Creatore, accepted for publication in Plasma Processes and Polymers (2010).