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Research topics
Last Update
24.08.2016
  • Materials for applications in optoelectronics and light-emitting devices;
  • Laser processing of solar cell materials;
  • Synthesis of macro- and nanoscopic crystal;
  • MOCVD synthesis of III-V nitride 0-D, 1-D and 2-D structures for LED applications;
  • Optical spectroscopy of fusion plasma and fusion reactor walls.

The main research topics:

1. Research and development of silicon thin film, nanocrystals and hybrid solar cells

Manufacturing of thin film amorphous silicon solar cells is perspective on condition of improving their efficiency and reducing production costs. Efficiency of amorphous silicon solar cells decreases with time due to formation of metastable light induced defects. Laser crystallization helps to cancel this effect. We apply visible laser wavelength for laser crystallization in contrast to widely used excimer laser crystallization, which able to process only ~100 nm thick a-silicon layer. Primary effects of laser crystallization of a-silicon are dopants activation, and increase of charge carrier mobility due to higher crystallinity of processed silicon. Additional effect is texturing of initially smooth surface, which decrease back reflection of incident light and increase solar cell efficiency.

Solution-processed nanocrystals quantum dot solar cells is a novel field in photovoltaics. Semiconducting nanocrystals possess many intriguing properties which are not present in corresponding bulk materials. Most famous is quantum confinement effect. Band gap widens in nanocrystals having diameter smaller than exciton bohr radius. Ability to produce nanocrystals of different band gap simply varying their size is highly important for effective utilization of solar spectrum and engineering of tandem solar cell architectures. Main advantage of nanocrystals for solar cell manufacturing is possibility of solution based deposition of nanocrystals thin films, which is many times less expensive in comparison to monocrystal silicon technology and even chemical vapor deposition technology.

Metal nanoparticles and nanowires are perspective for conductive polymer based tandem solar cells, which also can be solution processed. Metal nanoparticles deposited as intermediate layer between two subcells in tandem polymer cell works as recombination centers where holes and electrons recombine together. Metal nanowires are perspective material in plazmonics and recently employed for enhancing photon absorption in solar cells. Moreover, percolating networks of metal nanowires can be used as transparent conductive electrode, which is a mandatory component of every thin film solar cell. Recent publications proved that silver nanowires networks have electrical and optical parameters similar to ITO electrodes, which is etalon material in photovoltaics.

2. Metal nanoparticles and nanowires

Metal nanoparticles and nanowires are novel and perspective nanomaterials having wide range of possible applications. These materials can be synthesized using simple wet chemical methods. Metal nanopartciles and nanowires (Ag and Au) can be used in photonics and plasmonics, for single or double photon luminescence yield enhancement, photon absorption enhancement in solar cells, etc. Moreover, percolating networks of metal nanowires can be used as transparent conductive electrode, which is a mandatory component of every thin film solar cell. Recent publications proved that silver nanowires networks have electrical and optical parameters similar to ITO electrodes, which is etalon material in photovoltaics. We investigate mechanical, electroconductive and other properties of metal nanowires and hybrid core-shell (Ag/SiO2 nanowires), as well as laser processing methods of metal nanowires.

3. Optical spectroscopy of fusion plasma and fusion reactor walls.

Within the framework of EURATOM project „Laser Ablation Spectroscopy for Impurity Depth Profiling and Concentration Imaging in Plasma”, the laser ablation spectroscopy method for rapid qualitative and quantitative surface analysis of the first wall material of thermonuclear fusion reactors has been developed.

The formation and composition of thin layers, as well as the condition of the near-surface layers of the plasma-facing components are the crucial factors for the exploitation of materials in thermonuclear fusion reactors. Deposition of carbon layers, tungsten and carbon migration, as well as retention and diffusion of hydrogen isotopes are the major concerns in fusion devices.

The specific objectives of the project include characterization of the impurity concentration, profiling and erosion in ITER-relevant materials using laser ablation spectroscopy. The activities comprise development of the methodology for impurity concentration analysis depth profile and erosion in the tokamak hot wall tiles as well as elaboration of the concept for emerging technologies for in situ express characterisation of impurity profiling and migration of ITER-relevant materials.