Current Group Members
Research Focus: Transient dynamics and structural characterization of aggregated suspensions, nanoparticulates, and OFETs
Undergraduate University: UMBC
Hometown: Monrovia, MD
Tim graduated from UMBC in 2009 as a double major in chemistry and mathematics. He spent a year there as a TA and RA under Dr. Bradley Arnold, applying Laser Induced Fluorescence (LIF) measurements to remotely detect explosive materials before coming to JHU. He now studies aggregated nanoparticle suspensions and films of polymeric materials used within OPV devices, peptide-based materials designed to separate charge in biological settings, and prototypical OFET systems. Utilization of pump-probe and Raman spectroscopies answer key questions about the behaviors and dynamics of polarons and excitons within these ordered domains. Excited state Raman (FSRS), pump-re-pump-probe (PRP) and broadband polarization anisotropy(BPA) techniques clarify time-dependent dynamics and further elucidate material properties. Thus far, his contributions to the lab include updating a number of LabView data acquisition and analysis programs, analysis of the ideal methods through which to prepare nanoparticle suspensions and calibrate Raman data, and the construction/maintanence of the group’s website. In his spare time, he enjoys playing a variety of sports: (goalie of the infamous Buckyballs soccer team), playing the drums/games, and making people laugh with terrible puns!
Research Focus: Photoinduced non-adiabatic ring-closure dynamics of constrained stilbenoids
Undergraduate University: Shippensburg
Hometown: Dornsife, PA
Josh combines calculations with spectroscopic data to analyze the ring closure and excited state pathways of 1,2 diphenyl-cyclohexane (DPCH) and other terphenyl derivatives. His contributions to the lab have included constructing enclosures for the laser system, putting together a secondary, broadband, prism-based detection set-up, and maintanence/set-up of the servers used to run calculations by the group.
Research Focus: Charge transfer dynamics in photo-excited, plasmonic nanomaterials with an emphasis on catalytic reduction on semi-conductor substrate(s)
Undergraduate University: University of California Davis
Hometown: San Francisco, CA
Ken is originally from San Francisco and graduated from UC Davis with a B.S. in Chemistry. While there he participated in research with Ting Guo on possible cancer treatment and imaging techniques utilizing gold nanoparticles. He then worked as a staff research associate at UCSF. Working under Tracy McKnight in the department of Radiology and Biomedical Imaging he investigated the metabolic mechanisms associated with the malignant progression of brain tumors by correlating in vivo magnetic resonance imaging (MRI) and spectroscopic (MRS) features of human brain tumors with ex vivo measures of metabolism and other molecular alterations associated with tumor aggressiveness. Before joining the Bragg lab in 2013, he finished a masters program in physical chemistry at the University of San Francisco where he worked with Giovanni Meloni, studying reactive intermediates and products of possible biofuels using time resolved mass spectrometry at the Advanced Light Source at Laurence Berkeley National Labs.
Research Focus: Exploration of the 4TCE photoswitch (and relate species) using TAS and time-resolved FSRS
Graduate University: University of Warwick, UK
Hometown: Llanfallteg, Wales, UK
Jamie has recently joined the group after moving to the USA from the UK. He graduated with an undergraduate master’s degree in chemistry from the University of Warwick in 2012, after graduating he continued on at the same school and received his PhD under the excellent supervision of Dr Vas Stavros in 2016. His PhD research utilized time-resolved velocity map imaging (TR-VMI) and ion yield (TR-IY) techniques in order to explore photophyiscal relaxation processes and vibrational motion in “real time”. The main focus of his research attempted to unravel the intricacies of photoprotective mechanisms within biologically relevant chromophores.
First Year Students