Research
Our research targets the development and physical characterization of new functional inorganic materials with unusual electronic structures that give rise to desirable photophysical, photochemical, chemical, electronic, magnetic, or magneto-optical properties.
Synthesis: Our group is heavily involved in the synthesis of new inorganic materials on nanometer length scales. We are primarily focused on inorganic semiconductors. Synthesis is generally used in conjunction with spectroscopic measurements to cultivate a physical property of particular interest, but the syntheses themselves often require innovation and lead to new insights of fundamental importance.
Spectroscopy and Magnetism: We are using a wide array of analytical and spectroscopic probes to explore the physical properties of semiconductor nanocrystals and thin films. Techniques include electronic absorption, photoluminescence, magnetic circular dichroism (MCD), magneto-luminescence (MCPL), X-ray absorption, photoconductivity, and electron paramagnetic resonance (EPR) spectroscopies, as well as magnetic susceptibility. These physical studies are supplemented by theoretical electronic structure analyses.
Functional Properties: The combination of innovative syntheses and advanced spectroscopies under one roof offers the powerful opportunity to discover, develop, and ultimately harness the physical properties of new forms of matter. Samples can additionally be probed by simple chemical or redox perturbations to see how they respond, by electro- or photochemical techniques, or by assembly into functional architectures for specific applications, such as solar energy harvesting and conversion, or photodetection. Our iterative "make and measure" strategy accelerates materials development and yields a comprehensive understanding of the physical properties of these materials, bringing us closer to future technological applications.
Key thematic research areas include:
- spin-photonics: can we use dopant spins to control polarizations of emitted photons, and vice versa?
- nanocrystal redox chemistries: how do physical properties change when nanocrystals change their oxidation states?
- nanocrystal diffusion doping: is it possible to separate crystal growth from doping on the nanoscale?
- photoelectrochemistry at catalyst/mesostructure interfaces: how can surface electrocatalysts be used to modify semiconductor photoelectrochemistry?
- multi-electron nanocrystals: how can we introduce, stabilize, and study colloidal semiconductor nanocrystals containing multiple excess electrons, and what new physical properties emerge?
- new luminescent materials: can luminescent colloidal nanocrystals be used to solve long-standing phosphor challenges, or introduce fundamentally new phosphor properties?
- bandgap engineering: can we tune chemical, photochemical, or photoelectrical properties of semiconductor nanocrystals and thin films via bandgap engineering?
- improving interfaces in photovoltaics: can we combine spectroscopy and chemistry to identify and eliminate interfacial carrier traps in inorganic solar cells prepared by solution deposition methods?
Want to learn more? Check out the publications page.
colloidal ZnO DMS quantum dots