50 research outputs found
Molecular-Scale Interface Engineering of Nanocrystalline Titania by Co-adsorbents for Solar Energy Conversion
The use of mixed self-assembled monolayers, combining hydrophobic co-adsorbents with the sensitizer, has been demonstrated to enhance the efficiency of dye-sensitized solar cells (DSCs). Herein, the influence of the anchoring groups of the co-adsorbents on the performance of the DSCs is carefully examined by selecting two model molecules: neohexyl phosphonic acid (NHOOP) and bis-(3,3-dimethyl-butyl)-phosphinic acid (DINHOP). The effect of these co-adsorbents on the photovoltaic performance (JV curves, incident photon-to-electron conversion efficiency) is investigated. Photoelectron spectroscopy and electrochemical impedance spectroscopy are performed to assess the spatial configuration of adsorbed dye and co-adsorbent molecules. The photoelectron spectroscopy studies indicate that the ligands of the ruthenium complex, containing thiophene groups, point out away from the surface of TiO2 in comparison with the NCS group
Cation Dynamics in Mixed-Cation (MA)(x)(FA)(1-x)PbI3 Hybrid Perovskites from Solid-State NMR
Mixed-cation organic lead halide perovskites attract unfaltering attention owing to their excellent photovoltaic properties. Currently, the best performing perovskite materials contain multiple cations and provide power conversion efficiencies up to around 22%. Here, we report the first quantitative, cation-specific data on cation reorientation dynamics in hybrid mixed-cation formamidinium (FA)/methylammonium (MA) lead halide perovskites. We use N-14, H-2, C-13, and H-1 solid-state MAS NMR to elucidate cation reorientation dynamics, microscopic phase composition, and the MA/FA ratio, in (MA)(x)(FA)(1-x)PbI3 between 100 and 330 K. The reorientation rates correlate in a striking manner with the carrier lifetimes previously reported for these materials and provide evidence of the polaronic nature of charge carriers in PV perovskites
NMR of terminal oxygen. Part 7. Oxygen-17 NMR spectra of benzoyl derivatives of germanium, selenium, tellurium, and iodine: p-bond order and excitation energy in benzoyl compounds
Correlation of oxygen-17 substituent-induced chemical shifts: meta- and para-substituted methyl benzoates
NMR of terminal oxygen. Part 13. 17O-NMR spectra of C-nitroso compounds, thionitrites and NO+ ion: resonance effects in O:N-X compounds and correlation with CD spectra
Modified surface
The present invention relates to modified surfaces. The surfaces comprise an inorganic material on which a phosphinic acid derivative is adsorbed. The phosphinic acid thus turns out to be a new anchoring group useful for surface derivatisation. The invention has many applications for photoelectric conversion devices, batteries, capacitors, electrochromic displays, chemical sensors, biological sensors, light emitting diodes, electrodes, semiconductors, separation membranes, selective adsorbents, adsorbents for HPLC, catalysts, implants, nanoparticles, antiadhesives, and anticorrosion coatings, for example
NMR of terminal oxygen. Part 11. Oxygen-17 NMR spectra of disilyl ketone and related compounds: a case of strong deshielding by electronic excitation energy
Enantiomerically pure 7-oxabicyclo[2.2.1]hept-5-en-2-yl derivatives ("Naked sugars") as synthetic intermediates. Part XXII. Stereoselective synthesis of (1R)-1-C-(6-amino-7H-purin-8-yl)-1,4-anhydro-2,3-dideoxy-3-fluoro-D-erythro-pentitol
The "naked sugar" (+)-(1R,2S,4R)-2-cyano-7-oxa-bicyclo[2.2.1]hept-5-en-2-yl (1S)-camphanate [(+)-3] (Diels-Alder adduct of furan with 1-cyanovinyl (1S)-camphanate) was converted into (1R)-1-C-(6-amino-7H-purin-8-yl)-1,4-anhydro-2,3-dideoxy-3-fluoro-D-eryt hro-pentitol [(+)-2] in nine synthetic steps and 12% overall yield