InP Aerogels: Porous Semiconductors Stephanie L. Brock, Wayne State University, DMR The exploitation of nanocrystals in solid-state devices requires methods for assembling the nanoscopic objects into macroscopic objects. One powerful integration approach involves sol-gel routes, which produce highly porous nanostructures (aerogels). The nanostructure enables the intrinsic properties, such as the size-tunable bandgap of semiconductor nanocrystals, to be retained, and the pore structure enables access to the surface. Sol- gel methods are widely exploited in oxides, but semiconducting oxides have wide bandgaps that do not overlap well with the solar spectrum. In NSF-supported research, we demonstrate that an approach we developed for creation of metal chalcogenide aerogels can also be used to prepare phosphide materials, including the semiconductor InP. The visible light absorption capabilities of these materials along with the porosity makes them potentially suitable for hybrid solar cells and photocatalysis. In solution (a ‘sol’), InP nanocrystals appear transparent—they are too small to see with the naked eye. The color is indicative of a bandgap within the solar spectrum (it absorbs visible light). When hydrogen peroxide is added, it slowly de- protects the nanocrystals by removing molecules from the surface, enabling the particles to assemble together into a solid (a gel). However, this solid is not dense. When dried, it produces an aerogel with density <10% that of bulk InP. The low-density is due to the pore structure, which acts as a “super highway” for transport of molecules. This enables such semiconducting aerogels to be used for small molecule sensing or light-assisted decomposition. The sol-gel method of assembly is also suitable for catalytic phosphides, like Ni 2 P (sulfur removal from fuels), and magnetic phosphides, like MnP, enabling a range of properties to be incorporated.

Metro Detroit girls participate in GO-GIRLs Go Material Girls, a one-day outreach event where they made liquid crystals (LCs), created LC thermometers, and engaged in a game of “Materials Bingo” to test the knowledge gained over the course of the day. Meanwhile, Prof. Sally Roberts (a former teacher in the Detroit Public Schools) discussed effective strategies with the parents to ensure their daughters have the confidence and competence in STEM-related disciplines to succeed in college. GO-GIRLs Go Material Girls (G 3 MG) & Parent Café Stephanie L. Brock, Wayne State University, DMR As part of a comprehensive program at Wayne State University to direct girls into Science, Technology, Engineering, and Math (STEM) disciplines, GO-GIRLs Go Material Girls, a 1-day outreach event for Detroit area girls in 8-12 th grades, was developed and implemented for the first time on May 5 th, The module incorporated a brief college-style lecture, a wet-lab focused on liquid crystal synthesis, and a tour of the materials facilities at WSU. The lab content was developed and tested with the help of an undergraduate researcher, David Miga (pictured lower left) and graduate student Asha Bandara. Some 40 girls participated in the activity, led by 16 volunteers from WSU Chemistry. A Parent Café was also conducted to provide parents critical information to promote their daughter’s success.