Presentations

    Surface photochemistry of O2 on Pt(111) with femtosecond laser pulses, at 40th American Vacuum Society Conference (Orlando, FL), Friday, January 1, 1993
    Previous studies of O2 desorption and photoreaction from Pt(111)1 and Pd(111)2 upon irradiaiton with intense (>1mJ/cm2) 100fs laser pulses have observed highly nonlinear fluence dependences with power law exponents of 5 and higher. It has been proposed that multiple electronic transitions induce desorption either via coupling to transient high energy substrate electrons3 or more direct excitation.4
    Surface photochemistry of O2 on Pt(111) with femtosecond laser pulses, at 40th American Vacuum Society Conference (Orlando, FL), Friday, January 1, 1993
    Previous studies of O2 desorption and photoreaction from Pt(111)1 and Pd(111)2 upon irradiaiton with intense (>1mJ/cm2) 100fs laser pulses have observed highly nonlinear fluence dependences with power law exponents of 5 and higher. It has been proposed that multiple electronic transitions induce desorption either via coupling to transient high energy substrate electrons3 or more direct excitation.4
    Electron-beam-induced oxidation of benzene to phenol in C6H6/O2/Pt(111), at APS Centennial Meeting 1999 (Atlanta, GA), Tuesday, March 23, 1999:
    We have observed the formation of phenol when C6H6/O2/Pt(111) is exposed to a beam of electrons with energy on the order of 10-100 eV. With this sample preparation, the oxygen is bound directly to the platinum; the benzene overlayer does not displace the oxygen and chemisorb to the platinum. In contrast, no electron-beam-induced phenol production is observed when the benzene and oxygen are applied in the reverse order, for O2/C6H6/Pt(111). Following exposure to the electron beam, the yield of phenol is measured during temperature-programmed desorption. In the absence of the electron beam, no... Read more about Electron-beam-induced oxidation of benzene to phenol in C6H6/O2/Pt(111)
    Femtosecond laser doping of TiO2 for photocatalysis, at Photonics West (San Fransisco, CA), Monday, January 24, 2011:
    We present a novel method for femtosecond-laser doping of titanium dioxide (TiO2) for enhanced absorptance in the visible electromagnetic spectrum. With a bandgap of 3.2 eV for the anatase crystalline phase, TiO2 most strongly absorbs in the UV range ( < 387 nm). However, doping with metals and nitrogen has been shown to create intermediate states in the bandgap, generating a new material for visible-light photocatalysis that has the potential for watersplitting. Using femtosecond laser doping techniques on bulk TiO2 in a gaseous environment, we produce laser-induced periodic surface... Read more about Femtosecond laser doping of TiO2 for photocatalysis
    Femtosecond laser production of TiO2, at Hyperdoping Research Meetup, MIT (Cambridge, MA), Friday, April 15, 2011:
    We present a novel method for producing TiO2 through femtosecond-laser processing titanium in the presence of oxygen. The process produces laser-induced periodic surface structures that are consistent with previous work done on titanium. We compare how the surface morphology and composition vary with gas composition and laser parameters. Using x-ray photoelectron and Raman spectroscopy, we will show that chemical selectivity plays an important role in hyperdoping titanium. With this method, we hope to introduce dopants, such as chromium and nitrogen, into the lattice for visible light... Read more about Femtosecond laser production of TiO2