The Department of Physics is pleased to announce that Scott Melis is the recipient of the 2017 Professor Walter G. Mayer Endowed Scholarship, which supports a graduate student pursuing a Ph.D. in experimental physics. Scott's project involves studying the controlled formation of charge transfer cocrystal nanoparticles to better understand how to apply their useful properties. Careful selection of the two coformers can lead to the cocrystal possessing enhanced properties compared to each individual material. For example, high electron and hole mobility as well as photoconductive and photovoltaic states have all been reported in cocrystal materials. Scott's project so far has focused on phenothiazine (PTZ) and TCNQ as two coformers. Thus far, he has demonstrated the ability to grow PTZ:TCNQ cocrystals that are several hundred microns long and form in a fairly aligned series using a controlled evaporative self-assembly (CESA) technique.
Going forward, Scott plans to study further how this formation occurs, including what affects parameters such as concentration and solvent have on the process. To do this, fluorescence microscopy will be used to analyze the formation of these crystals as well as other optical diagnostics to map their growth under various initial conditions. With better knowledge of what controls the formation of these crystals, it will hopefully be possible apply the CESA method to other cocrystal combinations in addition to fabricating useful devices, such as a field effect transistor utilizing these PTZ:TCNQ crystals grown between electrodes.