Dorodnyy Alexander, Alarcon-Lladó Esther, Shklover Valery, Hafner Christian, Fontcuberta I Morral Anna, Leuthold Juerg (2015), Efficient Multiterminal Spectrum Splitting via a Nanowire Array Solar Cell., in ACS photonics
, 2(9), 1284-1288.
Dorodnyy Alexander, Shklover Valery, Braginsky Leonid, Hafner Christian, Leuthold Juerg (2015), High-efficiency spectrum splitting for solar photovoltaics, in Solar Energy Materials & Solar Cells
, 136, 120-126.
Boland Jessica, Conesa-Boj Sonia, Parkinson P, Tütüncüoglu Gözde, Matteini Federico, Rüffer Daniel, Casadei Alberto, Amaduzzi Francesca, Jabeen Fauzia, Davies CL, Joyce H, Hertz Laura M, Fontcuberta i Morral Anna, Johnston Michael B (2015), Modulation Doping of GaAs/AlGaAs Core-Shell Nanowires With Effective Defect Passivation and High Electron Mobility, in Nano Letters
, 15, 1336.
Matteini Federico, Dubrovskii Vladimir G., Rüffer Daniel, Tütüncüoglu Gözde, Fontana Yannik, Fontcuberta i Morral Anna (2015), Tailoring the diameter and density of self-catalyzed GaAs nanowires on silicon, in Nanotechnology
, 26, 105603.
Matteini Federico, Tütüncüoglu Gözde, Potts Heidi, Jabbed Fauzia, Fontcuberta i Morral Anna (2015), Wetting of Ga on SiOx and Its Impact on GaAs Nanowire Growth, in Crystal Growth & Design
, 15(7), 3105-3109.
Dalmau-Mallorqui Anna, Alarcon-Llado Esther, Russo-Averchi Eleonora, Tütüuncüoglu Gözde, Matteini Federico, Rüffer Daniel, Fontcuberta i Morral Anna (2014), Characterization and analysis of InAs/p–Si heterojunction nanowire-based solar cell, in Journal of Physics D
, 47, 394017.
Hafner Christian, Komarevskyi Nikolay, Dorodnyy Alexander, Boyvat Mustafa (2014), Electromagnetic Metamaterials - Promises, Design, and Applications, in Quantum Matter
, 3(4), 328-338.
Matteini Federico, Tütüuncüoglu Gözde, Rüffer Daniel, Alarcon-Llado Esther, Fontcuberta i Morral Anna (2014), Ga-assisted growth of GaAs nanowires on silicon, comparison of surface SiOx of different nature, in Journal of Crystal Growth
, 404, 246.
Dorodnyy Alexander, Shklover Valery, Hafner Christian, Leuthold Juerg (2014), Hybrid Approach Simulations for Light Propagation Problems, in 40th Photovoltaic Specialists Conference
, IEEE, Washington, USA.
Amaduzzi Francesca, Alarcon-Llado Esther, Russo-Averchi Eleonora, Heiss Martin, Matteini Federico, Tütüncuoglu Gözde, Conesa-Boj Sonia, de la Mata Maria, Arbiol Jordi, Fontcuberta i Morral Anna (2014), Probing inhomogeneous composition in core/shell nanowires by Raman spectroscopy, in Journal of Applied Physics
, 116, 184303.
Dorodnyy Alexander, Shklover Valery, Braginsky Leonid, Hafner Christian, Leuthold Juerg (2014), Spectrum splitting double-cell scheme for solar photovoltaics, in 40th IEEE Photovoltaic Specialists Conference
, IEEE, Washington, USA.
Gusak Viktoria, Heiniger Leo-Philipp, Zhdanov Vladimir, Grätzel Michael, Kasemo Bengt, Langhammer Christoph (2013), Diffusion and adsorption of dye molecules in mesoporous TiO2 photoelectrodes studied by indirect nanoplasmonic sensing, in Energy & Environmental Science
, 6, 3627-3636.
Dorodnyy Alexander, Shklover Valery, Hafner Christian (2013), HYBRID FEM-FMM APPROACH FOR EFFICIENT CALCULATIONS OF PERIODIC PHOTONIC STRUCTURES, in Progress In Electromagnetics Research M
, 33, 121-135.
Plasmonic light trapping in III-V materials is very dynamically developing solar cell research. Missions to outer planets, encountering problems of limited amount of solar power, the so-called low light intensity and low temperature (LILT) is one of the fields, which can benefit from this research. Harsh space conditions and the importance of low weight make the development of such cells for space extremely challenging and can only be accomplished by the achievements in several areas, which will be addressed in this project. The first area is based on revolutionary achievements in plasmonics and nanophotonics. The practical efficiency of multi-junction solar cells of the InGaAsN type, reduced at LILT to ~30%, shall be enhanced in this project. Two types of solar cells will be fabricated: nanowire solar cells (NWSC), providing larger light absorption than randomly structurized solar cells, and (2) nanostructure (nanolayer/quantum dots) modified multilayer solar cells (NSSC). Both NWSC and NSSC will be based on multi-junction III-V and II-V solar cells. Methods of plasmonic, patterning and waveguiding will be exploited. Several schemes of plasmonic enhancement will be tested: scattering by metal nanostructures located on the surface of the absorbing layer, by layers of small nanoparticles within the absorbing layer, and by surface plasmon polaritons at the boundary between the metal back contact and the semiconductor layer. The parameters determining the coupling efficiency of plasmonic enhancement, such as composition, shape, and size of nanoparticles, will be first optimized with simulations. Most promising optimized structures will be manufactured. Different schemes of patterning will be also first simulated and then studied experimentally. Solar light concentration by waveguiding can bring further advantages for space PV, especially for efficiency, cell area, and weight. Light concentrators can be of special importance under low light intensity. Concentrator systems need accurate solar pointing to maintain power production in the solar cell array. We will study the potential of solar concentration based on our previous work on waveguide couplers. Another challenge of this project will be the modification of the solar spectrum for obtaining a better match with the band gap of the applied semiconductors. The spectrum can be modified towards lower or higher energies via absorbing photons at certain wavelengths and emitting them at shorter or longer ones. Namely spectrum modifications by quantum dots or lanthanide-based glasses will be relevant for this project. Graded refractive index anti-reflection coatings on PV cells showed superior performance compared with classical AR coatings. A further enhancement of the efficiency can be reached by the deposition of an additional monolayer with sub-wavelength particle size on top of anti-reflective coatings. Metamaterial approach will be used for 1) efficient reduction of the reflection with less dependence on the angle of incidence, 2) direction of the transmitted wave into the absorbing layer, and 3) trapping the light within the absorber, as we have recently shown for ultra-thin radar absorbers. It is known that the efficiency of solar cells decreases with increasing temperature. Stability of designed solar cells (both material and light trapping) at temperature fluctuations up to 200 oC will be studied. On the contrary, low temperature in space is favorable in general. Furthermore, it can significantly alleviate the problem of absorption loss in metals, i.e., in plasmonic layers. At very low temperatures, even superconductivity can be reached, which might bring additional opportunities for light capturing, although plasmonic properties of superconductors are not yet well investigated. Basic types of known high-Tc superconductors shall be tested in the project. These superconductors are exhibiting essentially a layered structure and have a potentially advantageous deposition onto the multi-junction cell substrate. The project will also address radiation resistances and improved protection from the environment. Polyorganosilsesquioxanes are promising for covering the entire solar cell packaging. Atoms with high cross-sections may further increase the shielding properties, especially at stoichiometric amounts of transition metals and/or lanthanides. In order to ensure long-term operation of the solar cells, studies of their low-temperature stability will be performed. The dependence of the solar cell efficiency on temperature for different solar intensities for different space missions will be studied in detail. The exploration of adapted enhancement structures to LILT conditions and harsh outer space is the core of the project. The comparison and a combined use of several different approaches is another core. It is expected that the knowledge gained on light trapping enhanced solar cells, operating under LILT conditions, will also be valuable for the development of highly-efficient terrestrial III-V based solar cells, as the project results on low-temperature plasmonic, plasmonic in superconductors, operation of solar cell interconnectors at low-temperature, solar cell environmental stability and protection.