Surface Science and Engineering

    Surface science is the study of physical and chemical phenomena that occur at the interface of two phases, including solid-liquid interfaces, solid-gas interfaces, solid-vacuum interfaces, and liquid-gas interfaces. It includes the fields of surface chemistry and surface physics. Some related practical applications are classed as surface engineering. Our research activities in this area involve self-selective electroless plating, ultra-thin anodic aluminum oxide membranes, and metal patterning methods.

  1. T. Qiu* and P. K. Chu*, “Self-selective electroless plating: An approach for fabrication of functional 1D nanomaterials”, Materials Science and Engineering: R: Reports, vol. 61, no. 1 - 6, pp. 59 – 77 (2008). (highlighted as a cover image by Mater. Sci. Eng. R May, 2008)
  2. T. Qiu*, W. J. Zhang, X. Z. Lang, Y. J. Zhou, T. J. Cui, and P. K. Chu*, “Controlled assembly of highly Raman-enhancing silver nanocap arrays templated by porous anodic alumina membranes”, Small, vol. 5, no. 20, pp. 2333 – 2337 (2009).
  3. Q. Hao, H. Huang, X. C. Fan, Y. Yin, J. W. Wang, W. Li, T. Qiu, L. B. Ma*, P. K. Chu*, and O. G. Schmidt, “Controlled patterning of plasmonic dimers by using an ultrathin nanoporous alumina membrane as a shadow mask”, ACS Applied Materials & Interfaces, vol. 9, no. 41, pp. 36199 – 36205 (2017).

Surface-Enhanced Raman Scattering

    Raman spectroscopy is well known for its specificity in chemical and biological analysis, and offers some distinct advantages over other spectroscopic methods for homeland security applications. Due to the aggressive development of Raman technique, the discovery of surface-enhanced Raman scattering (SERS) in 1974 opened up a promising method to overcome the low sensitivity problem plaguing traditional Raman spectroscopy. SERS not only improves the surface sensitivity which makes Raman spectroscopy more applicable but also generates a stimulus for the study of the interfacial processes involving enhanced optical scattering from adsorbates on metal surfaces. The advent of SERS has spurred a worldwide effort to explore its origins, optimize it, and harness its potential in fields ranging from plasmonics to diagnostics. Our research activities in this area involve novel SERS platforms, advanced SERS technologies, SERS for sensing applications, and fundamental study of SERS origin.

  1. T. Qiu, X. L. Wu*, J. C. Shen, and P. K. Chu, “Silver nanocrystal superlattice coating for molecular sensing by surface-enhanced Raman spectroscopy”, Applied Physics Letters, vol. 89, no. 13, Article Number: 131914 (2006).
  2. D. Han, Y. F. Fang, D. Y. Du, G. S. Huang, T. Qiu*, and Y. F. Mei*, “Automatic molecular collection and detection by using fuel-powered microengines", Nanoscale, vol. 8, no. 17, pp. 9141 – 9145 (2016).
  3. X. Y. Hou, X. C. Fan, P. H. Wei, and T. Qiu*, “Planar transition metal oxides SERS chips: a general strategy", Journal of Materials Chemistry C, vol. 7, iss. 36, pp. 11134-11141 (2019).
  4. X. Y. Hou, X. Y. Zhang, Q. W. Ma, X. Tang, Q. Hao, and Y. C. Cheng*, T. Qiu*, “Alloy Engineering in Few‐Layer Manganese Phosphorus Trichalcogenides for Surface‐Enhanced Raman Scattering", Advanced Functional Materials , vol. 30, iss. 12, Article Number: 1910171 (2020).
  5. M. Z. Li, Y. M. Gao, X. C. Fan, Y. J. Wei, Q. Hao, and T. Qiu*, “Origin of layer-dependent SERS tunability in 2D transition metal dichalcogenides”, Nanoscale Horizons, vol. 6, iss. 2, pp. 186-191 (2021).

Plasmon-Enhanced Photoluminescence

    Since the early 1980s, enhancement of fluorescence from molecules near a metal nanostructure has been regarded to be associated with modification of the molecule excitation as well as the radiative and nonradiative decay rates. Nowadays, improved nanofabrication methods allow precise control of the nanoparticle shape and arrangement of nanoparticle ensembles thereby opening the possibility to flexibly tailor specific molecule-nanoparticle couplings. Our research activities in this area involve metal-enhanced fluorescence and surface-enhanced cellular fluorescence imaging.

  1. T. Qiu*, F. Kong, X. Q. Yu, W. J. Zhang, X. Z. Lang, and P. K. Chu, “Tailoring light emission properties of organic emitter by coupling to resonance-tuned silver nanoantenna arrays", Applied Physics Letters, vol. 95, no. 21, Article Number: 213104 (2009).
  2. T. Qiu*, J. Jiang*, W. J. Zhang, X. Z. Lang, X. Q. Yu, and P. K. Chu*, “High-sensitivity and stable cellular fluorescence imaging by patterned silver nanocap arrays”, ACS Applied Materials & Interfaces, vol. 2, no. 8, pp. 2465 – 2470 (2010).
  3. F. Kong*, X. Q. Zhang, X. Z. Lang, B. P. Lin, Y. M. Yang, and T. Qiu, “Band-gap-dependent emissions from conjugated polymers coupled silver nanocap array”, Applied Physics Letters, vol. 99, no. 23, Article Number: 233112 (2011).
  4. Q. Hao, T. Qiu*, and P. K. Chu*, “Surfaced-enhanced cellular fluorescence imaging”, Progress in Surface Science, vol. 87, no. 1 – 4, pp. 23 – 45 (2012).
  5. Q. Hao, J. Pang, Y. Zhang*, J. Wang, L. Ma, and O. G. Schmidt, “Boosting the Photoluminescence of Monolayer MoS2 on High-Density Nanodimer Arrays with Sub-10 nm Gap”, Advanced Optical Materials, vol. 6, iss. 2, Article Number: 1700984 (2018).

Hybrid Plasmonic Materials and Light-Matter Interactions

    The understanding and tailoring of nanoscale light-matter interactions in hybrid plasmonic materials is critical to many fields, offering valuable insights into the nature of materials, as well as allowing a variety of applications such as photocatalysis, detectors, and sensors. Our research activities in this area involve heterojunctions, plasmonic thermochromic smart coatings, and plasmonic photocatalysis.

  1. X. G. Luo, T. Qiu*, W. B. Lu*, and Z. H. Ni*, “Plasmons in graphene: recent progress and applications”, Materials Science and Engineering: R: Reports, vol. 74, no. 11, pp. 351 – 376 (2013).
  2. X. L. Liu, X. G. Luo, H. Y. Nan, H. Guo, P. Wang, L. L. Zhang, M. M. Zhou, Z. Y. Yang, Y. Shi*, W. D. Hu, Z. H. Ni, T. Qiu*, Z. F. Yu, J. B. Xu, and X. R. Wang*, “Epitaxial ultrathin organic crystals on graphene for high-efficiency phototransistors", Advanced Materials, vol. 28, no. 26, pp. 5200 – 5205 (2016).
  3. Q. Hao*, W. Li, H. Xu, J. Wang, Y. Yin, H. Wang, L. Ma, F. Ma, X. Jiang, O. G. Schmidt, and P. K. Chu*, “VO2/TiN Plasmonic Thermochromic Smart Coatings for Room-Temperature Applications”, Advanced Materials, vol. 30, iss. 10, Article Number: 1705421 (2018). {This work was highlighted in Advanced Science News (Jan 2018): Smart Window Coatings for Room-Temperature Applications.}
  4. M. Z. Li, X. C. Fan, Y. M. Gao, and T. Qiu*, “W18O49/Monolayer MoS2 Heterojunction-Enhanced Raman Scattering", The Journal of Physical Chemistry Letters, vol. 10, iss. 14, pp. 4038 - 4044 (2019).
  5. H. Huang, X. S. Wang, D. Philo, F. Ichihara, H. Song, Y. X. Li, D. Li, T. Qiu*, S. Y. Wang* and J. H. Ye*, “Toward visible-light-assisted photocatalytic nitrogen fixation: A titanium metal organic framework with functionalized ligands", Applied Catalysis B: Environmental, vol. 267, iss. 15, Article Number: 118686 (2020).