Dr. Heilweil's current research involves ultrafast infrared laser measurements using Fourier-transform instruments and infrared array detectors to perform time-resolved vibrational spectroscopy and non-contact optical approaches to extract semiconductor carrier dynamics. Far-infrared spectroscopy (Terahertz or THz) is employed to monitor chemical reactions on the femtosecond and longer timescales, measuring carrier conductivity and mobility in metals, organic conducting polymers, metal oxides, 2D nanolayered structures and novel organometallic (MOF) systems. Through pioneering efforts, he developed ultrafast broadband mid-infrared laser methods to examine vibrational energy transfer and identify photochemical processes in molecular solids and liquids. Using these approaches, he performed the first time-resolved vibrational lifetime measurements of adsorbates on dielectric and metal surfaces. These methods are now employed world-wide to study vibrational and carrier dynamics in complex condensed-phase systems. Ongoing investigations include collaborative work on biphasic chemical coordination in organometallic systems designed to function as ultrafast molecular switches (and memories) and directly monitoring processes in di-iron hydrogenase mimics to reveal hydrogen production mechanisms in bacteria.
Professional associations include current chair of the International Advisory Committee for the Time-Resolved Vibrational Spectroscopy conference (TRVS, co-chair in 2005 at NIST) and chairing the "Molecular Dynamics and Vibrational Spectroscopy" Gordon Conferences in 2000 and 2002. Dr. Heilweil was a Physical Chemistry Division Alternate Councilor (2003-2006) and a member of the American Chemical Society (since 1978), Coblentz Society (since 2003), Sigma Xi (since 1985), and became a Fellow of the Optical Society of America in 2008. He also served as an editorial advisory board member of the ACS Journal of Physical Chemistry from 2006 - 2012.
Heilweil began his career at NIST/NBS as a National Research Council Postdoctoral Fellow in 1983. He received several awards including the Instrument Society of America Beckman Award (1989), Department of Commerce Stratton Award (1991), and Sigma Xi Young Scientist Award (1992). In 2008 he received the NIST/DoC Silver Medal for "contributions to ultrafast optical studies of vibrational energy transfer and terahertz spectroscopy." He was recognized by receiving the Lifetime Achievement award from the TRVS community in 2017 for which a Special Issue in the journal Chemical Physics issued on his behalf in 2018. Heilweil also received a NIST/DoC Bronze Medal for work on Ultrafast Pulsed Laser Safety Eyewear in 2018. Heilweil has authored 154 technical papers, delivered 146 invited talks and holds two U.S. Patents.
Carrier Dynamics Measured by Ultrafast Time-Resolved Terahertz Spectroscopy