Lab


Our research expertise is in optics and photonics, as well as piezoelectric and optical materials. We study the fundamental science of propagation and manipulation of light, including lasers, as well as its interaction with physical matter. Specifically, we conduct research on measuring, understanding and enhancing the mechanical, electrical and optical properties of transducer-type materials to be used in functional devices and applications.

Transducer materials can either be natural or synthetic. They consist of transparent or opaque ceramics, polymers and glassy materials in crystalline, amorphous, bulk or thin-film forms. These materials are capable of actively changing a certain input energy signal, such as voltage, light signal or temperature variation into a different output energy signal, such as strain, refractive index change, electricity or light emission.

Currently, the following transducer effects are experimentally and theoretically researched in our group:

  • Photomechanical behaviour (light-induced molecular motion) and laser-induced nano-structures in azobenzene-containing materials.
  • Surface plasmon resonance, electromagnetic energy interaction between light and matter.
  • Photovoltaic properties of solar cells.
  • Photoluminescence and electroluminescence properties of organic compounds (OLEDs).
  • Electromechanical, which includes piezoelectric and electrostrictive effects.
  • Dielectric and polarization properties.
  • Electro-optic effects.
  • Thermo-optical effects.
  • Non-linear optical effects.

In recent years, our groupís main research theme has been on the laser nanofabrication of novel uniform, non-uniform and circular surface relief diffraction gratings in photomechanical azobenzene thin films. After fabrication, we incorporate these nanostructures in practical optical devices, such as electro-optical modulators, light waveguides and others. We also utilize our gratings for the generation of surface plasmon resonance on dielectric/metal interfaces for incorporation in a variety of light-based sensors and biosensors, as well as for enhancing the efficiency of organic thin film solar cells and light emitting diodes.

Below are a few pictures from our research:

SRG image

Laser-induced surface relief diffraction gratings (linear on the left and circular on the right)
.

Solar cells

Plasmonic organic thin film solar cells fabricated in our lab.


linear1

Atomic Force Microscope image of a linear surface relief diffraction grating on azo-glass thin film produced in our lab.

crossed

Atomic Force Microscope image of a crossed-superimposed surface relief diffraction grating on azo-glass thin film produced in our lab.

cloudiness 1

Atomic Force Microscope image of electric-field induced nanostructures on azo-glass thin film produced in our lab.

cloudiness 2

Atomic Force Microscope image of electric-field induced nanostructures on azo-glass thin film produced in our lab, at a wider view.

biosensor

Nanoplasmonic biosensor designed and tested in our lab for the detection of streptavidin−biotin−cysteamine via surface plasmon resonance and based on crossed surface relief gratings.

SEM SRG

Scanning Electron Microscope image of a surface relief diffraction grating produced in our lab.

SEM PZT

Scanning Electon Microscope image of a piezoelectric lead zirconate titanate ceramic.

SRG efficiency

Diffraction efficiency of a circular surface relief diffraction grating inscribed using a laser.

Photocurrent

Photocurrent enhancement in organic solar cells with surface plasmon resonance.

nanolithography

Nanolithography using our Bruker AFM, the image scale is approximately 2-3 times smaller than the average human hair.

Non-uniform grating

Arrow length is depicting grating pitch value, arrow direction is depicting grating vector orientation and colour map is depicting grating depth for a non-uniform diffraction grating fabricated in our lab.