RECENT NEWS
10.23.2019 - Please join us in welcoming our newest graduate students to the Korgel Group, Sejal Shah and Ben Stacy! Welcome!
10.02.2019 - Following up his recent podcast appearance, Tim Siegler will be giving a talk as a part of the UT Energy Symposium. Tim's talk, "The 10th Birthday of Perovskite Solar Cells - Will They Ever Grow Up?", will take place on October 10th. Interested attendees can register here.
09.27.2019 - Congrats to Korgel Group alumni and current professor at National Tsing Hua University in Taiwan, Dr. Hsing-Yu Tuan, for receiving the prestigious "Award for Outstanding Asian Researcher and Engineer" presented by the Society of Chemical Engineering of Japan. Great work, Hsing-Yu!
09.23.2019 - Did you miss Tim Siegler's talk with KVRX 91.7 earlier this month? If so, check out They Blinded Me with Science's discussion with Dr. Siegler on the future of perovskites here.
09.16.2019 - New paper from the Korgel Group! In Chemistry of Materials, Yangning Zhang et al. provide insight into the ligand binding and colloidal stability of Cs2AgBiBr6 double perovskite nanocrystals. Link
09.04.2019 - Congrats to Dr. Yuebing Zheng and his group for winning the University Co-op Research Excellence Best Paper Award for their paper Opto-Thermoelectric Nanotweezers, which also featured former Korgel Group member Emily Adkins as a supporting author.
07.31.2019 - Congratulations to Dr. Taizhi Jiang, who today successfully defended his thesis "Nanostructured Si and Ge for Applications in Batteries, Aerogels, and Metamaterials". Great work, Dr. TJ!
RESEARCH HIGHLIGHT
Thermal Phase Transitions in Superlattice Assemblies of Cuboidal CH3NH3PbI3 Nanocrystals Followed by Grazing Incidence X-ray Scattering
Methylammonium lead iodide (CH3NH3PbI3, or MAPI) is a prototypical lead halide perovskite material with promising optoelectronic properties for solar cells and light-emitting devices. In this paper, Yangning Zhang, Cherrelle Thomas, and Adrien Guillaussier reported the thermal phase transitions that occur in superlattices of MAPI nanocrystals observed using in-situ grazing incidence small-angle and wide-angle X-ray scattering (GISAXS and GIWAXS). GIWAXS shows that the nanocrystals have completed a tetragonal-to-cubic phase transition at 55-60C similar to bulk films and begin to degrade at 90C, when PbI2 begins to form. Both hexagonal and rhombohedral phases of PbI2 are observed as thermal degradation products at 150C. GISAXS shows that the superlattice remains stable until 90C. This work was done in collaboration with Dr. Smilgies at Cornell High Energy Synchrotron Source (CHESS) and was recently published in the Journal of Physical Chemistry C.
