Patterning and Imaging of Oxides on Glassy Carbon Electrode Surfaces by Scanning Electrochemical Microscopy

The scanning electrochemical microscope is used to form and characterize patterns of oxides on glassy carbon surfaces. Chemically specific imaging of oxides present on these surfaces was demonstrated by taking advantage of differential heterogeneous electrontransfer rates for the Fe(II/III) reaction occurring at unoxidized and oxidized glassy carbon electrodes. Localized generation of surface oxides was demonstrated using both the microreagent and direct modification modes of SECM. The micro-reagent mode was used to perform a chemical oxidation of the surface by generating the strong oxidant Ag(II) at the UME tip while positioned close to the carbon surface, however, this technique was found to have poor reproducibility. Direct mode oxidation was found to be a much more versatile route toward the generation of complex patterns of oxides on carbon surfaces. The reproducibility of the direct mode technique was found to depend heavily on solution resistance. “Charge dose” studies, followed by reaction-rate imaging, qualitatively show that the electron-transfer rate for the Fe(II/III) system scales with the amount of charge “injected” in each oxidation experiment, indicating a correlation between surface oxide density and electron-transfer rate

Optimizing Carbon Nanotube Contacts for Use in Organic Photovoltaics: Preprint

This report describes research on optimizing carbon nanotube networks for use as transparent electrical contacts (TCs) in organic photovoltaics (OPV)

Ultrathin and lightweight organic solar cells with high flexibility

Application-specific requirements for future lighting, displays and photovoltaics will include large-area, low-weight and mechanical resilience for dual-purpose uses such as electronic skin, textiles and surface conforming foils. Here we demonstrate polymer-based photovoltaic devices on plastic foil substrates less than 2 μm thick, with equal power conversion efficiency to their glass-based counterparts. They can reversibly withstand extreme mechanical deformation and have unprecedented solar cell-specific weight. Instead of a single bend, we form a random network of folds within the device area. The processing methods are standard, so the same weight and flexibility should be achievable in light emitting diodes, capacitors and transistors to fully realize ultrathin organic electronics. These ultrathin organic solar cells are over ten times thinner, lighter and more flexible than any other solar cell of any technology to date

NREL Energy Storage Projects -- FY2012 Annual Report

This report describes the activities of the Energy Storage group over FY2012

NREL Energy Storage Projects -- FY2012 Annual Report

This report describes the activities of the Energy Storage group over FY2012