Congrats to the RadiCold project team!

Welcome to the homepage of Prof. Xiaobo Yin's research group at the Department of Mechanical Engineering and the Materials Science and Engineering Program of the University of Colorado, Boulder. Go Buffs!

We are looking for motivated students and postdoctoral researchers in Nanomaterials and Nanophotonics!

Our research is focused on nanoscale materials and their applications: the interdisciplinary synergy of applied physics, materials sciences, and multiple sectors of engineering. We design and synthesize artificially nanomaterials with unprecedented properties; we explore technologies benefiting from material properties by design; and we develop devices with unique functionalities enabled by this materials engineering. More importantly, we develop manufacturing technologies that enable large-scale deployment of these innovative nanostructures and nanomaterials for advanced applications in photonic, electronic, and energy systems.

Materials in the Flatland: graphene and beyond

Non-trivial electronic properties stemming from the topologies and symmetries of nanomaterials such as graphene, topological insulators, and two-dimensional electron gases (2DEG) at the interfaces of perovskite oxides result in revolutionary nanophotonic and electronic applications. There have been tremendous opportunities to introduce controllable light flow and light-matter interactions into these still young materials systems to help reveal fundamental

unknown behaviors and properties and to identify new prospects for applications. The figure above shows the polarized nonlinear emission from a polycrystalline 2D transition metal dichalcogenide (MoS2) atomic membrane, which allows all-optical characterization of its crystal structure. Examples of 2D materials physics and applications:

Valley-spintronic light-emitting devices, Nature Nanotechnology 11, 598 (2016).

Excitonic Dark States in 2D Materials, Nature 513, 214 (2014).

Nonlinear Optical Materials, Science 344, 488 (2014).

Integrated Graphene Optical Modulators, Nature Materials 11, 936 (2012); Nature 474, 64 (2011).

Metamaterials: materials beyond the natural ones

Metamaterials, judiciously designed composite nanostructures, have emerged as a new frontier in science and engineering. The physical properties of a conventional material is essentially determined by its chemical constituents and bonds. However, the properties of a metamaterial are not limited by its composition but instead depend on its internal structure--leaving

tremendous degrees of freedom for materials design. It not only offers an entirely new route to further enhance materials’ physical properties but enables our ability to design entirely new material properties. The figure on the left illustrates a 2D metamaterial that generates and manipulates the spin-orbit interaction of light.

Examples of designer metamaterials:

Metamaterial that is highly nonlinear, Nature Materials 14, 379 (2015).

Metamaterial that self-assembles, Nature Nanotechnology 9, 1002 (2014).

Metasurface that manifests the photonic Spin hall effect, Science 339, 1405 (2013); Phys. Rev. A 93, 013839 (2016); Optics Express 24, 21177 (2016). Also see DoE Science Highlight.

Metamaterial that permits nonlinear optical conversion without phase matching, Science 342, 1223 (2013).

Metamaterial that provides unidirectional light propagation, Nature Materials 12, 175 (2013).

Metamaterial-enablement of the smallest existing optical cavity, Nature Photonics 6, 450 (2012).

Metamaterial that can "see" objects smaller than the diffraction limit of light, Nature Comm. 1, 143 (2011).

Metamaterial that boosts the resolutions of sonic imaging, Nature Physics 7, 52 (2011); Nature Materials 8, 931 (2009).

Manufacturing technology for nanostructures and nanomaterials at scale

The burgeoning research on nanomaterials and nanostructured materials has opened the door for numerous applications. However, widespread implementation is impeded by manufacturability. Scalable, precise, reliable, and cost-effective manufacturing approaches are critically needed. A different set of scientific and technological questions have to be asked and addressed to scale up fabrication and ultimately use nanostructured materials in real life. A recent thrust of my research addresses this fundamental manufacturing challenge, with our approach embracing both

novel scalable manufacturing techniques and innovative metamaterial structural designs. The right image shows our recently established Roll-to-Roll (R2R) Scalable Nanomanufacturing lab at the CU Engineering Center with a 300-mm-wide metamaterial thin film manufactured for highly efficient radiative cooling. Leveraging these uniquely developed manufacturing technologies, we also plan to develop and apply large-scale energy-converting metamaterials for building technology, solar fuel systems, and greenhouse technology. Example: Scalable-manufactured hybrid metamaterial for day-time radiative cooling, Science 355, 1062 (2017).

We are grateful for funding support from,

To visit, you can find us in Room 140 of the Discovery Learning Center in the Engineering and Applied Sciences Center at CU Boulder.

Group News


Congrats to the RadiCold team for winning the Breakthrough of the Year 2017, named by IOP Physics World!


Professor Yin gave the Kavli Foundation Early Career Lecture at the 2017 MRS Fall Conference, Boston, Massachusetts.


Gordon and Betty Moore Foundation announces 2017 Moore Inventor at the Tech Museum of San Jose, California, and Professor Yin was elected as one of the inventors.


Professor Yin gave an invited talk at the 2017 OSA Light, Energy and the Environment Congress at National Center for Atmospheric Research (NCAR), Boulder, Colorado.


Professor Yin was invited to participate the 2017 Frontier of Engineering (FOE) conference organized by National Academy of Engineering (NAE) at the United Technology Research Center (UTRC), East Hartford, Connecticut.


Professor Yin gave an invited talk at the 2017 Annual AVS Rocky Mountain Chapter Symposium, Westminster, Colorado.


Professor Yin gave an invited talk at the 2017 SPIE Optics and Photonics Conference, San Diego, California.


Professor Yin gave an invited talk at the 2017 CLEO Pacific Rim, OECC, and PGC, Singapore


Professor Yin visited Institute of Materials Research and Engineering (IMRE) of Agency for Science, Technology and Research (A*STAR), and delivered an invited seminar, Singapore.


Professor Yin gave an invited talk at the 8th International Conference on Metamaterials, Photonic Crystals and Plasmonics, Seoul, Korea.


Professor Yin gave a keynote speech at the 4th international conference on phononic crystal/metamaterials, phonon transport/coupling and topological phononics, Changsha, China.


Professor Yin gave a invited speech on the advances on metaphotonic devices at CLEO 2017, San Jose, California.


Congrats to Yao, who just received the NKT Student Award at MRS Spring Meeting at San Francisco!


Congrats to RadiCold team! Having great research shows at both 2017 ARPA-E Summit and Capitol Hill, the United States Congress.


Congrats to Yao, Yaoguang, Sabrina, and Runnan for their Science paper appeared online! Thank you all for the great work!


Professor Yin presented an invited seminar at SunPower Inc., San Jose, California.


Professor Yin visited National Renewable Energy Laboratory (NREL), Golden, Colorado.


Professor Yin presented an invited talk at the 53rd Annual Technical Meeting of Society of Engineering Science, Maryland.


Professor Yin presented an invited talk at the 3rd International Conference on Phononics and Thermal Energy Science (PTES 2016), Xi'an, China.

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