Brad R. Weiner

Chemistry Graduate and Undergraduate Professor

Research Interests
Physical Chemistry: Gas Phase Molecular Reaction Dynamics; Laser Photochemistry and Photophysics; Gas Phase Kinetics of Reactive Intermediates; Non-Linear Photoprocesses; Molecular Energy Transfer; Mechanisms of Laser Ablation.

The detailed mechanisms of elementary unimolecular and bimolecular reactions are not well understood. In part, the problem lies in the difficulty of monitoring the evolution of highly reactive, short-lived intermediates during the course of the reaction. Our research applies a host of modern spectroscopic (primarily laser-based) techniques to understand the structure and reactivity of said transient species in the gas phase. In recent years, this research has focused on the chemistry of gas phase sulfur-containing species.

These studies have important overlap with current theoretical problems and are also relevant to the chemistry of high-energy gas phase environments, such as the upper and lower atmosphere, and combustion systems. Another area of interest in our research program is the development of new techniques and methodology for the detection of reactive intermediates. In particular, multiphoton processes are being investigated as a new means of probing polyatomic molecules of real world interest. Applications to atmospheric systems and microelectronic device fabrication are being explored.

S. Gupta, B. R. Weiner and G. Morell, Ex situ spectroscopic ellipsometry investigations of chemical vapor deposited nanocomposite carbon thin films, Thin Solid Films, 455, 422-428 (2004).

S. Gupta, G. Morell and B. R. Weiner, Electron field-emission mechanism in nanostructured carbon films: a quest, J. Appl. Phys., 95, 8314-8320 (2004).

S. Gupta, G. Morell and B. R. Weiner, Role of H in hot-wire deposited a-Si:H films revisited: optical characterization and modeling, J. Non-Cryst. Solids, 343, 131-142 (2004).

S. Gupta, B. R. Weiner, W. H. Nelson and G. Morell, Ultraviolet and visible Raman spectroscopic investigations of nanocrystalline carbon thin films grown by bias-assisted hot-filament chemical vapor deposition, J. Raman Spectrosc., 34, 192-198 (2003).

Feng, P.X. and Brad R. Weiner, High Abundance of Metastable Helium Atoms for Diagnostic Applications, J. Phys. B: At., Mol. Opt. Phys., 37, 1-5 (2004).

Adolfo Gonzalez-Berrios, Dachun Huang, Nadia M. Medina-Emmanuelli, Kathleen E. Kristian, Oscar O. Ortiz, Juan A. Gonzalez, Joel De Jesus, Iris M. Vargas, Brad R. Weiner and Gerardo Morell, Effects of heavy-ion radiation on the electron field emission properties of sulfur-doped nanocomposite carbon films, Diamond Relat. Mater., 13, 221-225 (2004).

S. Gupta, B. R. Weiner and G. Morell, Influence of sulfur incorporation on field-emission properties of microcrystalline diamond thin films, J. Mater. Res., 18, 2708-2716 (2003).

Kathleen E. Kristian, Nadia M. Medina-Emmanuelli, Oscar O. Ortiz, Adolfo Gonzalez, Juan A. Gonzalez, Joel De Jesus, Iris M. Vargas, Brad R. Weiner and Gerardo Morell, Study of the effects of heavy-ion radiation on nanocomposite carbon films, Mater. Res. Soc. Symp. Proc., 777, 189-194 (2003).

Joel De Jesus, Juan A. Gonzalez, Oscar O. Ortiz, Brad R. Weiner and Gerardo Morell, Parallel bias-enhanced sulfur-assisted chemical vapor deposition of nanocrystalline diamond films, Mater. Res. Soc. Symp. Proc., 775, 325-330 (2003).

F. A. M. Kock, J. M. Garguilo, R. J. Nemanich, S. Gupta, B. R. Weiner and G. Morell, Spatial distribution of electron emission sites for sulfur doped and intrinsic nanocrystalline diamond films, Diamond Relat. Mater., 12, 474-480 (2003).

Yuchuan Gong, Vladimir I. Makarov and Brad R. Weiner, Time-resolved Fourier transform infrared study of the 193 nm photolysis of SO 2, Chem. Phys. Lett., 378, 493-502 (2003).

S. Gupta, B. R. Weiner and G. Morell, Synthesis and characterization of sulfur-incorporated microcrystalline diamond and nanocrystalline carbon thin films by hot filament chemical vapor deposition, J. Mater. Res., 18, 363-381 (2003).

S. Gupta, B. R. Weiner and G. Morell, Room-temperature electrical conductivity studies of sulfur-modified microcrystalline diamond thin films, Appl. Phys. Lett., 83, 491-493 (2003).

Joel De Jesus, Juan A. Gonzalez, Brad R. Weiner, and Gerardo Morell, Studies of Doped Nanocrystalline Diamond Films Grown by Parallel Bias-enhanced Chemical Vapor Deposition, IEEE Nano 2003 Conference Proceedings, 2, 480 (2003).