Advanced Photonics, Vol. 2, Issue 4, 046004 (2020)
Spatial and spectral mode mapping of a dielectric nanodot by broadband interferometric homodyne scanning near-field spectroscopy
Jinxin Zhan1, Wei Wang2, Jens Brauer1, Lukas Schmidt-Mende2, Christoph Lienau1,*, and Petra Groß1,*
- 1Carl von Ossietzky Universität, Institut für Physik and Center of Interface Science, Oldenburg, Germany
- 2University of Konstanz, Department of Physics, Konstanz, Germany
We investigate the optical properties of nanostructures of antimony sulfide (Sb2S3), a direct-bandgap semiconductor material that has recently sparked considerable interest as a thin film solar cell absorber. Fabrication from a nanoparticle ink solution and two- and three-dimensional nanostructuring with pattern sizes down to 50 nm have recently been demonstrated. Insight into the yet unknown nanoscopic optical properties of these nanostructures is highly desired for their future applications in nanophotonics. We implement a spectrally broadband scattering-type near-field optical spectroscopy technique to study individual Sb2S3 nanodots with a 20-nm spatial resolution, covering the range from 700 to 900 nm. We show that in this below-bandgap range, the Sb2S3 nanostructures act as high-refractive-index, low-loss waveguides with mode profiles close to those of idealized cylindrical waveguides, despite a considerable structural disorder. In combination with their high above-bandgap absorption, this makes them promising candidates for applications as dielectric metamaterials, specifically for ultrafast photoswitching.
Please Enter Your Email: