Student Thesis Prize Awards
The Kavli ENSI Thesis Prize Committee is pleased to announce the recipients of the best Thesis Prize. Nominations are reviewed based on the quality of the work, publication status, strength of up to two supporting letters, CV of the nominee, and relevance of the thesis to the Kavli mission. The prize will be presented biannually after the thesis deadlines in May and December of each year.
2015 - 2016 Kelsey Sakimoto
Converting sunlight to chemicals in an efficient, reliable, and inexpensive manner is a grand challenge of the century. My thesis sheds some light on a potential approach, combining high efficiency semiconductor based light harvesters, and higher performance biological catalysis for CO2 fixation. This work covers the design of a bacterium that synthesizes and uses inorganic nanoparticles for photosynthesis, enabling self-replicating solar-to-chemical production. I also begin the exploration of the mechanism behind the new form of charge transfer between semiconductor and bacterium, driving the future investigations of how these new forms of life tick. These insights guide our work as we embark on version 2.0
2014 - 2015 Dr. Noah Bronstein
Bronstein's dissertation highlights a path to achieve high photovoltaic conversion efficiency in luminescent solar concentrators, devices which absorb sunlight with a luminescent dye and then re-emit it into a waveguide where it is ultimately collected by a photovoltaic cell. Luminescent concentrators have been studied for more than three decades as potential low-cost but not high efficiency photovoltaics. Astute application of the black body radiation law indicates that photonic design is necessary to achieve high efficiency: a reflective filter must be used to trap luminescence at all angles while allowing higher energy photons to pass through. In addition, recent advances in the synthesis of colloidal nanomaterials have created the possibility for lumophores with broad adsoption spectra, narrow-bandwidth emission, high luminescence quantum yield, tunable Stokes shifts and tunable Stokes ratios. Together , these factors allow luminescent solar concentrators to achieve the optical characteristics necessary for high efficiency. The first generation of these devices was fabricated and tested. The devices achieved the highest luminescent concentration factors yet recorded in literature while maintaining high photon collection efficiency.
2014 - 2015 Dr. Daniel Goldman
During translation, the ribosome reads the genetic code of the messenger RNA, adding one amino acid at a time to the nascent polypeptide. In order to carry out it's biological function, the polypeptide must fold to the native state, and the folding process can begin before translation is complete. Goldman's thesis work has focused on ribosome-nascent chain interactions that affect both the folding process and the activity of the ribosome. Using a novel optical tweezers assay, we observed folding transitions of single ribosome-bound nascent polypeptides. We found that the ribosome can modulate the kinetics of folding, guiding the protein to the native state.
2013 - 2014 Dr. Long Ju
Ju's thesis describes the use of optical spectroscopy in studying the physical properties of two dimensional nano materials like graphene and hexogonal boron nitride. Compared to bulk materials, atomically thin two dimensional materials are unique in that both electronic band structure and chemical potential can be tuned in situ by electric field. Therefore optical studies in such systems greatly benefit from modern micro-facbrication technique and electric control of the material properties. This thesis demonstrated a few examples of new possibilities in material science by combining opticap spectroscopy with other experimental techniques, such as electric transport and STM measurements. These experiments are driven by important problems in 2D materials but are generally beyond the reach of each individual technique.
2013 - 2014 Dr. Ziliang Ye
Ye's dissertation is devoted to study the range of fascinating optical 'dark' effects that emerge in the nanoscale and usually cannot be probed by the linear optical spectroscopy or imaging in the far field zone. The studied systems are consisted of two parts: artificlal plasmonic antennas and natural two dimensional transiiton metal dichalcogenides (TMCDs). With plasmonic antennas, I realize the classical analog of a few intriguing quantum mechanical effects, including electromagnetic induced transparency, anti-Hermitian coupling induced super-radiance, and spin Hall effect for photon. Because most of these effects only occur in the subdiffractional scale, I develop a nearfield scanning tunneling microscopy with a super-resolution to observe these 'dark' effects. In the study of 2D TMDC, I discover several excitonic states are originated from a very large exciton binding energy in the unique 2D semiconducting material. Using another nonlinear optical probe, second harmonic generation spectroscopy, I further identify an edge response at the domain boundary of a continuous TMDC crystal synthesized by the chemical vapor deposition technique. Finally, a TMDC exciton based light emitting device is demonstrated as a practical application.