He Wang Group Lab

Our research interests focus on investigating device physics and photophysics of organic and organic-inorganic hybrid perovskite materials and structures. Such fundamental study can be useful design motif to realize high-performance and low-cost optoelectronic devices. We utilize ultrafast laser spectroscopy to understand carrier dynamics and synchrotron based X-ray techniques to characterize materials structure. Combining with the study on device physics, we seek to better understand basic physics, chemistry, and potential application of next-generation solar cells, light-emitting diodes, transistors, and lasers.

 

 

Interest 1: Device Physics Interest 2: Photophysics Interest 3: Characterization
  • Efficient, stable, large-area metal halide perovskite solar cells
  • Device physics such as interfacial engineering and carrier dynamics
  • Blade coating/slot die and scaleup perovskite technology
    Photophysical properties, such as carrier lifetime, carrier spin lifetime, charge transfer, coherent phonon, using transient absorption and reflection speoctroscopy, for
  • perovskite materials   
  • organic ligand protected nanoclusters
  • Structure characterization via XRD and synchrotron based X-ray techniques
  • Structure-photophysics-function relationship of perovskite materials and organic solar cells
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  • News

    • He Wang received 2021 DURIP and 2017 AFOSR YIP award.
    • He Wang received 2017 Provost Research Award at University of Miami.

  • People


    PI: He Wang

     

    • University of Miami, Department of Physics
      June 2022 - present, Associate Professor
      August 2016 - May 2022, Assistant Professor
      Award: 2017 AFOSR YIP
    • UC Berkeley and LBNL
      Postdoctoral Fellow
      October 2013 - June 2016
      Advisor: Prof. Graham Fleming
    • Princeton University
      PhD in Electrical Engineering
      September 2008 - September 2013
      Advisor: Prof. Yueh-Lin (Lynn) Loo
    • Tsinghua University, China
      Bachelor in Materials Science and Engineering
      September 2004 - July 2008
    • National Tsing Hua University, Taiwan
      Exchange student in Materials Science and Engineering
      March 2007 - July 2007

     

    Current Group Members

    Julio Sarmiento
    Graduate Student
    Project: ultrafast laser spectroscopy
    Pramod Baral
    Graduate Student
    Project: Perovskite solar cells and modules
    Xinwen Zhang
    Graduate Student
    Project: Perovskite solar cells and modules
    Zikun Cao
    Graduate Student
    Project: Perovskite solar cells and modules

     

    Alumni

    Dr. Chengbin Fei
    Postdoc
    Project: Perovskite solar cells
    Time in group: 08/2017 - 08/2020
    Dr. Meng Zhou
    Postdoc
    Project: Ultrafast laser spectroscopy
    Time in group: 05/2018-05/2020

     

    • Rocio Rivera: Undergraduate 2017 Spring
      Current position: graduate student at University of Virginia
    • Max Hew: Undergraduate 2017 Summer
      Current position: undergraduate student at University of Miami

     

  • Photos

    Equipment

     

    Spectroscopy Lab

    • Renovated lab with temperature and humidity control to study photophysics of different materials

    • Ultrafast laser (800 nm 35 femtosecond 5KHz) and optical parametric amplifier (OPA) to create visible and near infrared pulse

    • Transient absorption and reflection spectroscopy in visible and near infrared (femtosecond and nanosecond)

    • Time correlated single photon counting (TCSPC) and CCD camera
      UV-vis absorption

    • Cryogenic experiments (liquid nitrogen)

    Lab for device fabrication

    • Two nitrogen-filled glove boxes connected with vacuum thermal evaporator (six sources and co-evaporation) for device fabrication; solar simulator and dual-channel Keithley for device test

     

    • fume hood, laminar flow cabinet, UV-ozone, balance, hotplate, spin coater, oven, homely-built hot spray, blade coater, slot die, lock-in amplifier

      

    • maximum power point tracking (MPPT) for solar cell devices

      

    Shared Facilities

    • XRD in Physics Department
    • SEM, photolithography, surface profiler, AFM, PECVD, parylene coater, magnetron sputtering in the Biomedical Nanotechnology Institute at University of Miami (BioNIUM)

  • Publication

    Publication

    Google scholar citation >1700 (update June  2022)
    http://scholar.google.com/citations?user=7ubxtmYAAAAJ&hl=en

    Independent work
    39. X. Zhang, L. Shen, P. Baral, S. N. Vijayaraghavan, F. Yan, X. Gong*, H. Wang*. “Blade-coated inverted perovskite solar cells in an ambient environment” Solar Energy Materials and Solar cells, accepted, 2022.
    38. Y. Li, Y. Song, X. Zhang, T. Liu, T. Xu, H. Wang, D. Jiang, R. Jin*. “Atomically Precise Au42 Nanorods with Longitudinal Excitons for an Intense Photothermal Effect” Journal of the American Chemical Society, accepted, 2022.
    37. L. Shen, T. Zhu, X. Zhang, K. Gong, H. Wang*, X. Gong*. “Bulk heterojunction perovskite solar cells incorporated with p-type low optical gap conjugated polymers” Nano Energy, 2022, 93, 106907.
    36. T. Zhu, L. Shen, S. Xun, J. S Sarmiento, Y. Yang, L. Zheng, H. Li*, H. Wang*, J.-L. Bredas*, X. Gong*. “High-performance ternary perovskite-organic solar cells” Advanced Materials, 2022, 34, 2109348.
    35. X. Du, H. Ma, X. Zhang, M. Zhou, Z. Liu, H. Wang*, G. Wang*, R. Jin*. “Single-electron charging and ultrafast dynamics of bimetallic Au144-xAgx(PET)60 nanoclusters” Nano Research, 2022, accepted.
    34. W. Zhang, J. Kong,Y. Li, Z. Kuang, H. Wang, R. Jin, M. Zhou*.“Coherent Vibrational Dynamics of Au144(SR)60 Nanoclusters” Chemical Science, 2022, accepted.
    33. D. Powell, Z. Rhodes, X. Zhang, E. J. Miller, M. Jonely, K. R. Hansen, C. I. Nwachukwu, A. G. Roberts, H. Wang, R. Noriega, S. D. Minteer, L. Whittaker-Brooks*. “Photoactivation Properties of Self-n-Doped Perylene Diimides: Concentration-dependent Radical Anion and Dianion Formation” ACS Materials Au, 2022, https://doi.org/10.1021/acsmaterialsau.2c00019.
    32. M. Zhou, X. Du, H. Wang*, R. Jin*. “The Critical Number of Gold Atoms for a Metallic State Nanocluster: Resolving a Decades-Long Question” ACS nano, 2021, 15, 13980. (Review)
    31. Y. Li†, M. Zhou†, Y. Song†, T. Higaki, H. Wang, R. Jin*. “Double-helical assembly of heterodimeric nanoclusters into supercrystals” Nature, 2021, 594, 380.
    30. Y. Song*, Y. Li, M. Zhou, X. Liu, H. Li, H. Wang, Y. Shen, M. Zhu*, R. Jin*. “Ultrabright Au@Cu14 Nanoclusters: 71.3% Phosphorescence Quantum Yield in Non-degassed Solution at Room Temperature” Science Advances, 2021, 7, eabd2091.
    29. Y. Li, M. J. Cowan, M. Zhou, T.-Y. Luo, Y. Song, H. Wang, N. L. Rosi, G. Mpourmpakis*, R. Jin*.“Atom-by-Atom Evolution of the Same Ligand-Protected Au21, Au22, Au22Cd1, and Au24 Nanocluster Series” Journal of the American Chemical Society, 2020, 142, 20426.
    28. J. Li, A. Chew, S. Han , J. Li , Y. Wu, H. Wang, S. Ghimire, Z. Chang*.“Attosecond Science based on High Harmonic Generation from Gases and Solids” Nature Communications, 2020, 11, 2748. (Perspective)
    27. Y. Li, M. J. Cowan, M. Zhou, M. G. Taylor, H. Wang, Y. Song*, G. Mpourmpakis*, R. Jin*. “Heterometal-Doped M23 (M= Au/Ag/Cd) Nanoclusters with Large Dipole Moments” ACS Nano, 2020, 14, 6599.
    26. M. Zhou, J. Sarmiento, C. Fei, X. Zhang, H. Wang*. “Effect of Composition on the Spin Relaxation of Lead Halide Perovskites” The Journal of Physical Chemistry Letters, 2020, 11, 1502.
    25. M. Titze, C. Fei, M. Munoz, X. Wang, H. Wang, H. Li*. “Ultrafast Carrier Dynamics of Dual Emissions from Orthorhombic Phase in Methylammonium Lead Iodide Perovskites Revealed by Two-Dimensional Coherent Spectroscopy” The Journal of Physical Chemistry Letters, 2019, 10, 4625. (selected as cover)
    24. M. Zhou†, J. S. Sarmiento†, C. Fei, H. Wang*. “Charge Transfer and Diffusion at the Perovskite/PCBM Interface Probed by Transient Absorption and Reflection” The Journal of Physical Chemistry C, 2019, 123, 22095.
    23. C. Fei, M. Zhou, J. Ogle, D.-M. Smilgies, L. Whittaker-Brooks, H. Wang*. “Self-Assembled Propylammonium Cations at Grain Boundaries and Film Surface to Improve Efficiency and Stability of Perovskite Solar Cells” Journal of Materials Chemistry A, 2019, 7, 23739. (2019 Emerging Investigator Themed Issue)
    22. M. Zhou†, C. Fei†, J. S. Sarmiento, H. Wang*. “Manipulating Phase Distribution and Carrier Transfers in Hybrid Quasi-Two-Dimensional Perovskite Films” Solar RRL, 2019, 3, 1800359. (This article is selected by Wiley hot topic: solar cells)
    21. C. Fei, H. Wang*. “Age-Induced Recrystallization in Perovskite Solar Cells”Organic Electronics, 2019, 68, 143.
    20. X. Shan, S. Zhang, M. Zhou, T. Geske, M. Davis, A. Hao, Z. Liang, H. Wang, Z. Yu*. “Porous Halide Perovskite-Polymer Nanocomposites for Explosive Detection with A High Sensitivity” Advanced Materials Interfaces, 2019, 6, 1801686.
    19. C. Fei, J. S. Sarmiento, H. Wang*. “Generation of Coherent Optical Phonon in Methylammonium Lead Iodide Thin Films” The Journal of Physical Chemistry C, 2018, 122, 17035.
    Graduate and Postdoctoral Research

    18. H. Wang, L. Valkunas, T. Cao, L. Whittaker-Brooks, G. R. Fleming. “Coulomb Screening and Coherent Phonon in Methylammonium Lead Iodide Perovskites” The Journal of Physical Chemistry Letters, 2016, 7, 3284.
    17. H. Wang, L. Whittaker-Brooks, G. R. Fleming. “Exciton and Free Charge Dynamics of Methylammonium Lead Iodide Perovskites are Different in the Tetragonal and Orthorhombic Phases” The Journal of Physical Chemistry C, 2015, 119, 19590.
    16. A. M. Hiszpanski, J. D. Saathoff, L. Shaw, H. Wang, L. Kraya, F. Luttich, M. A. Brady, M. L. Chabinyc, A. Kahn, P. Clancy, Y.-L. Loo. “Halogenation of a Nonplanar Molecular Semiconductor to Tune Energy Levels and Bandgaps for Electron Transport” Chemistry of Materials, 2015, 27, 1892.
    15. H. Wang, J. M. Mativetsky, Y. Ren, E. D. Gomez, C. Jaye, J. Schwartz, D. A. Fischer, Y.-L. Loo. “Fluorinated and Hydrogenated Self-Assembled Monolayers (SAMs) on Anodes: Effects of SAM Chemistry of Device Characteristics of Polymer Solar Cells” Organic Electronics, 2014, 15, 3333.
    14. J. M. Mativetsky, H. Wang, S. Lee, L. Whittaker-Brooks, Y.-L. Loo. “Face-On Stacking and Enhanced Out-of-Plane Hole Mobility in Graphene-Templated Copper Phthalocyanine” Chemical Communications, 2014, 50, 5319.
    13. A. Dai, Y. Zhou, A. L. Shu, S. K. Mohapatra, H. Wang, C. Fuentes-Hernandez, Y. Zhang, S. Barlow, Y.-L. Loo, S. R. Marder, B. Kippelen, A. Kahn. “Enhanced Charge-Carrier Injection and Collection via Lamination of Doped Polymer Layers p-Doped with a Solution-Processible Molybdenum Complex” Advanced Functional Materials, 2014, 24, 2197.
    12. H. Wang, E. D. Gomez, Z. Guan, C. Jaye, M. F. Toney, D. A. Fischer, A. Kahn, Y.-L. Loo. “Tuning Contact Recombination and Open-Circuit Voltage in Polymer Solar Cells via Self-Assembled Monolayer Adsorption at the Organic-Metal Oxide Interface” The Journal of Physical Chemistry C, 2013, 117, 20474.
    11. H. Wang, M. Shah, C. Jaye, D. A. Fischer, V. Ganesan, M. Chabinyc, Y.-L. Loo. “Comment on ‘Tail State-Assisted Charge Injection and Recombination at the Electron-Collecting Interface of P3HT:PCBM Bulk-Heterojunction Polymer Solar Cells’” Advanced Energy Materials, 2013, 3, 1537.
    10. A. M. Hiszpanski, S. S. Lee, H. Wang, A. R. Woll, C. Nuckolls, Y.-L. Loo. “Post-Deposition Processing Methods to Induce Preferential Orientation in Contorted Hexabenzocoronene Thin Films” ACS Nano, 2013, 7, 294.
    9. A. Shu, A. Dai, H. Wang, Y.-L. Loo, A. Kahn. "Electronic Structure and Carrier Transport at Laminated Polymer Homojunctions" Organic Electronics, 2013, 14, 149.
    8. Y. A. Getmanenko, M. Fonari, C. Risko, B. Sandhu, E. Galan, L. Zhu, P. Tongwa, D. K. Hwang, S. Singh, H. Wang, S. P. Tiwari, Y.-L. Loo, J.-L. Bredas, B. Kippelen, T. Timofeeva, S. R. Marder. “Benzo[1,2-b:6,5-b']dithiophene(dithiazole)-4,5-Dione Derivatives: Synthesis, Electronic Properties, Crystal Packing and Charge Transport” Journal of Materials Chemistry C, 2013, 1, 1467.
    7. H. Wang, M. Shah, V. Ganesan, M. Chabinyc, Y.-L. Loo. “Tail State-Assisted Charge Injection and Recombination at the Electron-Collecting Interface of P3HT:PCBM Bulk-Heterojunction Polymer Solar Cells” Advanced Energy Materials, 2012, 2, 1447.
    6. K. Kuribara, H. Wang, N. Uchiyama, K. Fukuda, T. Yokota, U. Zschieschang, C. Jaye , D. Fischer, H. Klauk, T. Yamamoto, K. Takimiya, M. Ikeda, H. Kuwabara, T. Sekitani, Y.-L. Loo, T. Someya. “Organic Transistors with High Thermal Stability for Medical Applications” Nature Communications, 2012, 3, 723.
    5. S. Fabiano, C. Musumeci, Z. Chen, A. Scandurra, H. Wang, Y.-L. Loo, A. Facchetti, B. Pignataro. “From Monolayer to Multilayer N-Channel Polymeric Field-Effect Transistors with Precise Conformational Order” Advanced Materials, 2012, 24, 951.
    4. H. Wang, E. D. Gomez, J. B. Kim, Z. Guan, C. Jaye, D. A. Fischer, A. Kahn, Y.-L. Loo. “Device Characteristics of Bulk-Heterojunction Polymer Solar Cells are Independent of Interfacial Segregation of Active Layers” Chemistry of Materials, 2011, 23, 2020.
    3. S. Fabiano, H. Wang, C. Piliego, C. Jaye, D. A. Fischer, Z. Chen, B. Pignataro, A. Facchetti, Y.-L. Loo, M.A. Loi. “Supramolecular Order of Solution-Processed Perylenediimide Thin Films: High-Performance Small-Channel n-Type Organic Transistors” Advanced Functional Materials, 2011, 21, 4479.
    2. E. D. Gomez, K. P. Barteau, H. Wang, M. F. Toney, Y.-L. Loo. “Correlating the Scattered Intensities of P3HT and PCBM to the Current Densities of Polymer Solar Cells” Chemical Communications, 2011, 47, 436.
    1. Z.-L. Guan, J. B. Kim, H. Wang, C. Jaye, D. A. Fischer, Y.-L. Loo, A. Kahn. “Direct Determination of the Electronic Structure of the Poly(3-hexylthiophene):phenyl-[6,6]-C61 Butyric Acid Methyl Ester Blend” Organic Electronics, 2010, 11, 1779.

     

     

  • Contact Information

    He Wang
    Associate Professor
    Department of Physics, University of Miami

    Email: hewang@miami.edu

    Tel:+1 (305) 284 7126
    Fax: +1(305) 284 4222


    Office address: 1320 Campo Sano Ave, Rm 315, Coral Gables, FL 33146 , US
    Lab address: 1320 Campo Sano Ave, Rm 129, Coral Gables, FL 33146, US