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Dye-sensitized solar cells based on titanium dioxide (TiO(2)) are promising low-cost alternatives to conventional solid-state photovoltaic devices based on materials such as Si, CdTe and CuIn(1-x)Ga(x)Se(2) (refs 1, 2). Despite offering relatively high conversion efficiencies for solar energy, typical dye-sensitized solar cells suffer from durability(More)
Lead-free solution-processed solid-state photovoltaic devices based on methylammonium tin iodide (CH 3 NH 3 SnI 3) perovskite semiconductor as the light harvester are reported. Featuring an optical bandgap of 1.3 eV, the CH 3 NH 3 SnI 3 perovskite material can be incorporated into devices with the organic hole-transport layer spiro-OMeTAD and show an(More)
Recent advances in polymer solar cell (PSC) performance have resulted from compressing the bandgap to enhance the short-circuit current while lowering the highest occupied molecular orbital to increase the open-circuit voltage. Nevertheless, PSC power conversion efficiencies are still constrained by low fill factors, typically below 70%. Here, we report(More)
The influence of solubilizing substituents on the photovoltaic performance and thin-film blend morphology of new benzo[1,2-b:6,5-b']dithiophene (bBDT) based small molecule donor semiconductors is investigated. Solar cells based on bBDT(TDPP)2-PC71BM with two different types of side chains exhibit high power conversion efficiencies, up to 5.53%.
We describe the first synthesis of the C1-phosphonate analog of UDP-GlcNAc, based on a new preparation of the corresponding glycosyl phosphonate. This C-glycosyl analog is shown to be a very weak inhibitor (Ki>10 mM) of fungal chitin synthase, indicating that at least in this case the replacement of the anomeric oxygen with a methylene group is not an(More)
Perovskite-based solar cells have recently been catapulted to the cutting edge of thin-film photovoltaic research and development because of their promise for high-power conversion efficiencies and ease of fabrication. Two types of generic perovskites compounds have been used in cell fabrication: either Pb- or Sn-based. Here, we describe the performance of(More)
We report experimental and theoretical studies of the random lasing threshold and its fluctuation in an ensemble of highly packed spherical dielectric scatterers. The ratio of the sphere diameter to the lasing wavelength was varied in a wide range, which covered the transition from the weak Rayleigh scattering regime to the strong Mie scattering regime.(More)
A series of experiments have been carried out to study the effects of materials quality, surface and interfacial modification, and photon confinement on standard dye-sensitized solar cells. For these studies, both physical and optical characterization of the materials has been performed in detail. In addition, DC and AC impedance measurements along with(More)
We studied numerically and experimentally the effects of structural disorder on the performance of ultraviolet photonic crystal slab lasers. Optical gain selectively amplifies the high-quality modes of the passive system. For these modes, the in-plane and out-of-plane leakage rates may be automatically balanced in the presence of disorder. The spontaneous(More)
Zinc-indium-tin oxide (ZITO) films are grown by pulsed-laser deposition in which 30% of the indium in the In(2)O(3) structure is replaced by substitution with zinc and tin in equal molar proportions: In(2-2x)Zn(x)Sn(x)O(3), where x = 0.3. Films grown at 25 and 100 degrees C exhibit electron diffraction patterns (EDPs) typical of amorphous materials. At a(More)