Browsing by Subject "Solar Energy"

Now showing 1 - 4 of 4

Open Access
Photovoltaic nanocrystal scintillators hybridized on Si solar cells for enhanced conversion efficiency in UV
(Optical Society of American (OSA), 2008) Mutlugun, E.; Soganci I.M.; Demir, Hilmi Volkan
We propose and demonstrate semiconductor nanocrystal based photovoltaic scintillators integrated on solar cells to enhance photovoltaic device parameters including spectral responsivity, open circuit voltage, short circuit current, fill factor, and solar conversion efficiency in the ultraviolet. Hybridizing (CdSe)ZnS core-shell quantum dots of 2.4 nm in diameter on multi-crystalline Si solar cells for the first time, we show that the solar conversion efficiency is enhanced 2 folds under white light illumination similar to the solar spectrum. Such nanocrystal scintillators provide the ability to extend the photovoltaic activity towards UV. © 2008 Optical Society of America.
Open Access
Plasmonically enhanced hot electron based photovoltaic device
(Optical Society of American (OSA), 2013) Atar F.B.; Battal, E.; Aygun L.E.; Daglar, B.; Bayındır, Mehmet; Okyay, Ali Kemal
Hot electron photovoltaics is emerging as a candidate for low cost and ultra thin solar cells. Plasmonic means can be utilized to significantly boost device efficiency. We separately form the tunneling metal-insulator-metal (MIM) junction for electron collection and the plasmon exciting MIM structure on top of each other, which provides high flexibility in plasmonic design and tunneling MIM design separately. We demonstrate close to one order of magnitude enhancement in the short circuit current at the resonance wavelengths. © 2013 Optical Society of America.
Open Access
Triangular metallic gratings for large absorption enhancement in thin film Si solar cells
(Optical Society of American (OSA), 2012) Battal, E.; Yogurt, T.A.; Aygun L.E.; Okyay, Ali Kemal
We estimate high optical absorption in silicon thin film photovoltaic devices using triangular corrugations on the back metallic contact. We computationally show 21.9% overall absorptivity in a 100-nmthick silicon layer, exceeding any reported absorptivity using single layer gratings placed on the top or the bottom, considering both transverse electric and transverse magnetic polarizations and a wide spectral range (280 - 1100 nm). We also show that the overall absorptivity of the proposed scheme is relatively insensitive to light polarization and the angle of incidence. We also discuss the implications of potential fabrication process variations on such a device. © 2012 Optical Society of America.
Open Access
Understanding the plasmonic properties of dewetting formed Ag nanoparticles for large area solar cell applications
(Optical Society of American (OSA), 2013) Günendi, M.C.; Tanyeli I.; Akgüç G.B.; Bek, A.; Turan, R.; Gülseren O.
The effects of substrates with technological interest for solar cell industry are examined on the plasmonic properties of Ag nanoparticles fabricated by dewetting technique. Both surface matching (boundary element) and propagator (finite difference time domain) methods are used in numerical simulations to describe plasmonic properties and to interpret experimental data. The uncertainty on the locations of nanoparticles by the substrate in experiment is explained by the simulations of various Ag nanoparticle configurations. The change in plasmon resonance due to the location of nanoparticles with respect to the substrate, interactions among them, their shapes, and sizes as well as dielectric properties of substrate are discussed theoretically and implications of these for the experiment are deliberated. ©2013 Optical Society of America.