Xiong, Wei
Investigation of Charge Dynamics and Molecular Conformations at Interfaces

Contact Information

Assistant Professor of Chemistry and Biochemistry

Office: Pacific Hall B100C
Phone: 858-534-0270
Email: w2xiong@ucsd.edu
Web: ultrafast.ucsd.edu
Group: View group members

Education
2011 Ph.D., University of Wisconsin, Madison
2006 B.S., Peking University

Appointments
2014 Asst. Professor, UCSD
2011 Postdoc, University of Colorado, Boulder

Awards and Academic Honors

2019

NSF CAREER Award

2017

DARPA Director's Fellowship

2016

AFOSR Young Investigator Program Award (YIP)

2015

DARPA Young Faculty Award (YFA)

Research Interests

1. Theoretical results demonstrate that interfacial molecular conformations directly influence charge separation dynamics in polymer blend solar cells. Experimentally, it would be very beneficial to be able to monitor the interaction between interfacial conformations and dynamics. However, since charge separation mostly happens at disordered hidden interfaces in thick samples, it is very challenging to capture such processes using existing spectroscopic techniques. We will develop ultrafast surface sensitive spectroscopy to follow both the charge separation dynamics and interfacial conformation simultaneously.

2. The chemical physics of electrocatalysts is complicated and remain a challenge to study, because it happens right at the interfaces. Understanding the microscopic molecular properties at liquid/solid interfaces will be the key for designing new catalysts for better selectivity and lower overpotential. We are specialized in a new interface sensitive technique, called heterodyne 2D SFG spectroscopy, which are able to follow ultrafast dynamics at interfaces. We are interested in using it to determine molecular structure and dynamics of catalysts at liquid/solid interfaces, and transition dynamics in situ.

3. Many Interfaces of materials are heterogeneous. Thus, it would be powerful to visualize molecular conformations and dynamics without confusions from spatial ensemble averaging. We are interested in developing heterodyne SFG based microscopy to visualize heterogeneous interfaces, including MOFs, host-guest self-assemblies, and sea surface monolayers

Primary Research Area
Physical/Analytical Chemistry

Interdisciplinary interests

Materials
Atmospheric and Environmental

Image Gallery

HD SFG Microscopy

CO2 surface catalysts probed by HD 2D SFG

Selected Publications

F Ribeiro R,Dunkelberger AD,Xiang B,Xiong W,Simpkins BS,Owrutsky JC,Yuen-Zhou J "Theory for Nonlinear Spectroscopy of Vibrational Polaritons.", J Phys Chem Lett, 2018, Vol. 9, Issue 13, 3766-3771 [View Abstract]

Lauren E.Buchanan, WeiXiong "Two-Dimensional Infrared (2D IR) Spectroscopy", Encyclopedia of Modern Optics (Second Edition), 2018, Vol. 2, 164-183

Shrestha M,Luo M,Li Y,Xiang B,Xiong W,Grassian VH "Let there be light: stability of palmitic acid monolayers at the air/salt water interface in the presence and absence of simulated solar light and a photosensitizer.", Chem Sci, 2018, Vol. 9, Issue 26, 5716-5723 [View Abstract]

Xiang B,Ribeiro RF,Dunkelberger AD,Wang J,Li Y,Simpkins BS,Owrutsky JC,Yuen-Zhou J,Xiong W "Two-dimensional infrared spectroscopy of vibrational polaritons.", Proc Natl Acad Sci U S A, 2018, Vol. 115, Issue 19, 4845-4850 [View Abstract]

Haoyuan Wang, Tian Gao, and Wei Xiong "Self-Phase-Stabilized Heterodyne Vibrational Sum Frequency Generation Microscopy", ACS Photonics, 2017, Vol. 4, Issue 7, 1839

Xiang B,Li Y,Pham CH,Paesani F,Xiong W "Ultrafast direct electron transfer at organic semiconductor and metal interfaces.", Sci Adv, 2017, Vol. 3, Issue 11, e1701508 [View Abstract]

Ellis JL,Hickstein DD,Xiong W,Dollar F,Palm BB,Keister KE,Dorney KM,Ding C,Fan T,Wilker MB,Schnitzenbaumer KJ,Dukovic G,Jimenez JL,Kapteyn HC,Murnane MM "Materials Properties and Solvated Electron Dynamics of Isolated Nanoparticles and Nanodroplets Probed with Ultrafast Extreme Ultraviolet Beams.", J Phys Chem Lett, 2016, Vol. 7, Issue 4, 609-15 [View Abstract]

Yingmin Li, Jiaxi Wang, Melissa Clark, Clifford P. Kubiak, Wei Xiong "Characterizing interstate vibrational coherent dynamics of surface adsorbed catalysts by fourth-order 3D SFG spectroscopy", Chem. Phy. Lett., 2016, Vol. 650, Issue 16, 1

Zhiguo Li, Jiaxi Wang, Yingmin Li, and Wei Xiong "Solving the “Magic Angle” Challenge in Determining Molecular Orientation Heterogeneity at Interfaces", JPCC, 2016, Vol. 120, Issue 36, 20239

Jennifer L Ellis, Daniel D Hickstein, Kyle J Schnitzenbaumer, Molly B Wilker, Brett B Palm, Jose L Jimenez, Gordana Dukovic, Henry C Kapteyn, Margaret M Murnane, Wei Xiong "Solvents effects on charge transfer from quantum dots", JACS, 2015, Vol. 137, Issue 11, 3759-3762

Jiaxi Wang, Melissa L. Clark, Yingmin Li, Camille L. Kaslan, Clifford P. Kubiak, and Wei Xiong "Short-Range Catalyst–Surface Interactions Revealed by Heterodyne Two-Dimensional Sum Frequency Generation Spectroscopy", JPCL, 2015, Vol. 6, 4204-4209

Yingmin Li, Jiaxi Wang, and Wei Xiong "Probing Electronic Structures of Organic Semiconductors at Buried Interfaces by Electronic Sum Frequency Generation Spectroscopy", JPCC, 2015, Vol. 119, Issue 50, 28083

Ding C, Xiong W, Fan T, Hickstein DD, Popmintchev T, Zhang X, Walls M, Murnane MM, Kapteyn HC, "High flux coherent super-continuum soft X-ray source driven by a single-stage, 10mJ, Ti:sapphire amplifier-pumped OPA.", Opt Express, 2014, Vol. 22, Issue 5, 6194-202 [View Abstract]

Hickstein DD, Dollar F, Ellis JL, Schnitzenbaumer KJ, Keister KE, Petrov GM, Ding C, Palm BB, Gaffney JA, Foord ME, Libby SB, Dukovic G, Jimenez JL, Kapteyn HC, Murnane MM, Xiong W. "Mapping nanoscale absorption of femtosecond laser pulses using plasma explosion imaging.", ACS Nano, 2014, Vol. 8, Issue 9, 8810-8818 [View Abstract]

Hickstein DD, Dollar F, Gaffney JA, Foord ME, Petrov GM, Palm BB, Keister KE, Ellis JL, Ding C, Libby SB, Jimenez JL, Kapteyn HC, Murnane MM, Xiong W, "Observation and control of shock waves in individual nanoplasmas.", Phys Rev Lett, 2014, Vol. 112, Issue 11, 115004 [View Abstract]

Xiong W, Hickstein DD, Schnitzenbaumer KJ, Ellis JL, Palm BB, Keister KE, Ding C, Miaja-Avila L, Dukovic G, Jimenez JL, Murnane MM, Kapteyn HC, "Photoelectron spectroscopy of CdSe nanocrystals in the gas phase: a direct measure of the evanescent electron wave function of quantum dots.", Nano Lett, 2013, Vol. 13, Issue 6, 2924-30 [View Abstract]

Laaser JE, Xiong W, Zanni MT, "Time-domain SFG spectroscopy using mid-IR pulse shaping: practical and intrinsic advantages.", J Phys Chem B, 2011, Vol. 115, Issue 11, 2536-46 [View Abstract]

Xiong W, Laaser JE, Mehlenbacher RD, Zanni MT, "Adding a dimension to the infrared spectra of interfaces using heterodyne detected 2D sum-frequency generation (HD 2D SFG) spectroscopy.", Proc Natl Acad Sci U S A, 2011, Vol. 108, Issue 52, 20902-7 [View Abstract]

Woys AM, Lin YS, Reddy AS, Xiong W, de Pablo JJ, Skinner JL, Zanni MT, "2D IR line shapes probe ovispirin peptide conformation and depth in lipid bilayers.", J Am Chem Soc, 2010, Vol. 132, Issue 8, 2832-8 [View Abstract]

Xiong W, Laaser JE, Paoprasert P, Franking RA, Hamers RJ, Gopalan P, Zanni MT, "Transient 2D IR spectroscopy of charge injection in dye-sensitized nanocrystalline thin films.", J Am Chem Soc, 2009, Vol. 131, Issue 50, 18040-1 [View Abstract]

Xiong W, Zanni MT, "Signal enhancement and background cancellation in collinear two-dimensional spectroscopies.", Opt Lett, 2008, Vol. 33, Issue 12, 1371-3 [View Abstract]