Best Practices for Reporting on Heterogeneous Photocatalysis

20 08 2014

Best Practices for Reporting on Heterogeneous Photocatalysis

Paper

Jillian M. Buriak (Editor-in-Chief, Chemistry of Materials) ,
University of Alberta
Prashant V. Kamat (Deputy Editor, The Journal of Physical Chemistry Letters) ,
University of Notre Dame
Kirk S. Schanze (Editor-in-Chief, ACS Applied Materials & Interfaces)
University of Florida
ACS Appl. Mater. Interfaces, 2014, 6 (15), pp 11815–11816
DOI: 10.1021/am504389z




Mariam Mirzakhani wins the Field Medal of Mathematics

13 08 2014

A professor of mathematics at Stanford University in California, iranian-native Mariam Mirzakhani won the 2014 Field Medal of Mathematics and becomes the first woman winner. The panel appreciated the Mirzakhani’s innovative contributions in the dynamics and geometry of Riemann surfaces and their moduli spaces.

The Fields Medal is awarded every 4 years to at most 4 mathematicians under 40 years. It is regarded as the highest honor a mathematician can receive.

more information

Maryam-Mirzakhani





Organic photoelectrochemical cells for solar fuel production

7 08 2014

Organic donor-acceptor blends like P3HT-PCBM have been greatly improved in recent years providing high efficiency and stable solar cells. These materials are cheap and versatile. They can be very promising for the production of solar fuels. To this aim the photocurrent must be extracted to an electrolyte to produce the required chemical reactions in solution. This is different than the normal operation of PV cells with two solid contacts. We have developed an important step in this direction showing that the photocurrent of standard organic blends can be extracted quantitatively to a liquid contact for either oxidative or reductive action. We show the extraction of 4 mA cm2 in an organic photoelectrochemcial cell (OPEC) which is the same that the solar cell produces at 1 sun without reflective back layer. This is just a first step , as it is required to find suitable catalytic/protective layers at the organic/liquid interface for water splitting or CO2 reduction, say. But we believe there is a great potential in this system for solar energy conversion.

Organic photoelectrochemical cells with quantitative photocarrier conversion

Antonio Guerrero,   Marta Haro,   Sebastiano Bellani,  Maria Rosa Antognazza,   Laura Meda,   Sixto Gimenez and  Juan Bisquert  
Energy Environ. Sci., 2014

DOI: 10.1039/C4EE01775G
First published online 07 Aug 2014

EES 10 1039C4EE01775G

 

 





Capacitance of perovskite solar cells

31 07 2014

There have been many questions in conferences about the capacitance of perovskite solar cells, as the show very surprising properties. We have studied this matter for some time and now we give an opinion at the level of theory, also confirmed by experimental data.

 

Theory of Impedance and Capacitance Spectroscopy of Solar Cells with Dielectric Relaxation, Drift-Diffusion Transport and Recombination

Juan Bisquert , Luca Bertoluzzi , Ivan Mora-Sero , and Germà Garcia-Belmonte
J. Phys. Chem. C, Just Accepted Manuscript
DOI: 10.1021/jp5062144
Publication Date (Web): July 30, 2014
capacitance perovskite
Abstract
Semiconductor photovoltaic devices currently investigated, such as hybrid organic-inorganic lead halide perovskite based solar cells, have shown a high dielectric polarization combined with ambipolar carrier transport. In this work we present a new model that takes into account both features by combining the classical drift-diffusion equation with a generalized Poisson equation that involves a density and frequency dependent dielectric constant that accounts for the polarization of the medium. We derive the corresponding transmission line (TL) and analyse the associated complex plane impedance spectroscopy (IS) and capacitance spectra. The standard dielectric constant is replaced by the dielectric relaxation element that depends on the frequency, which provides a dielectric relaxation subcircuit in the middle rail of the TL. After simplification of the TL, three arcs can be observed: the first one, at low frequency, is associated to the dielectric relaxation process, the second one, at intermediate frequency, is the drift-diffusion/recombination arc and the last one, at high frequency, corresponds to the geometric capacitance in parallel with transport resistances for both electrons and holes. In the case in which only two semicircles are observed, the parameters that can be extracted are the recombination and dielectric relaxation resistances along with the chemical and dielectric relaxation capacitances. The density dependent static dielectric constant gives rise to current generators that produce exotic impedance spectra associated to inductive behaviour. These results provide a major tool for the determination of physical characteristics of lead halide perovskite solar cells.




DOE Energy Frontier Research Centers awarded

4 07 2014

U.S. Energy Secretary Ernest Moniz today announced the awarding of $100 million for Energy Frontier Research Centers (EFRCs) to accelerate the scientific breakthroughs needed to build the 21st-century energy economy

 

Energy Frontier Research Centers (EFRCs)





Insights about physical mechanisms in perovskite solar cells

23 06 2014

Photoinduced Giant Dielectric Constant in Lead Halide Perovskite Solar Cells

J. Phys. Chem. Lett.Just Accepted
Publication Date (Web): June 23, 2014 (Letter)
DOI: 10.1021/jz5011169

Slow Dynamic Processes in Lead Halide Perovskite Solar Cells. Characteristic Times and Hysteresis

J. Phys. Chem. Lett.Just Accepted
Publication Date (Web): June 18, 2014 (Letter)
DOI: 10.1021/jz5011187




How to draw Figures correctly

19 06 2014

The new issue of JPCLett editorial on Graphical Excellence explains how to draw Figures correctly. It presents important instructions that the authors can follow while preparing graphics for a scientific publication. J. Phys. Chem. Lett., 2014, 5 (12), pp 2118–2120
DOI: 10.1021/jz500997e http://pubs.acs.org/doi/pdfplus/10.1021/jz500997e








Follow

Get every new post delivered to your Inbox.

Join 58 other followers