Sonia R. Raga

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Changes in the composition of the electrolyte are known to affect the parameters that determine the performance of dye solar cells. This paper describes a robust method for the analysis of the photovoltage in dye solar cells. The method focuses on the study of recombination resistance and chemical capacitance of TiO2 obtained from impedance spectroscopy.(More)
Three alkoxy-wrapped push-pull porphyrins were designed and synthesized for dye-sensitized solar cell (DSSC) applications. Spectral, electrochemical, photovoltaic and electrochemical impedance spectroscopy properties of these porphyrin sensitizers were well investigated to provide evidence for the molecular design.
We fabricated perovskite solar cells using a triple-layer of n-type doped, intrinsic, and p-type doped 2,2',7,7'-tetrakis(N,N'-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD) (n-i-p) as hole transport layer (HTL) by vacuum evaporation. The doping concentration for n-type doped spiro-OMeTAD was optimized to adjust the highest occupied molecular(More)
SiO2 Aerogel Templated, Porous TiO2 Photoanodes for Enhanced Performance in Dye-Sensitized Solar Cells Containing a Ni(III)/(IV) Bis(dicarbollide) Shuttle Tina C. Li, Francisco Fabregat-Santiago,* Omar K. Farha, Alexander M. Spokoyny, Sonia R. Raga, Juan Bisquert, Chad A. Mirkin,* Tobin J. Marks,* and Joseph T. Hupp* Department of Chemistry, Argonne(More)
In the standard solar cell technologies such as crystalline silicon and cadmium telluride, increments of temperature in the cell produce large variations in the energy conversion efficiency, which decreases at a constant rate. In dye solar cells the efficiency remains roughly constant with a maximum at around 30-40 °C and further decays above this(More)
For the first time, we intentionally deposit an ultrathin layer of excess methylammonium iodide (MAI) on top of a methylammonium lead iodide (MAPI) perovskite film. Using photoelectron spectroscopy, we investigate the role of excess MAI at the interface between perovskite and spiro-MeOTAD hole-transport layer in standard structure perovskite solar cells(More)
The rapid rise of power conversion efficiency (PCE) of low cost organometal halide perovskite solar cells suggests that these cells are a promising alternative to conventional photovoltaic technology. However, anomalous hysteresis and unsatisfactory stability hinder the industrialization of perovskite solar cells. Interface engineering is of importance for(More)
Low-bandgap diketopyrrolopyrroleand carbazolebased polymer bulk-heterojunction solar cells exhibit much faster charge carrier recombination kinetics than that encountered for less-recombining poly(3-hexylthiophene). Solar cells comprising these polymers exhibit energy losses caused by carrier recombination of approximately 100 mV, expressed as reduction in(More)
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