NSF Award
2213441
Non-technical Description. Providing precise, localized temperature control is important for many applications, such as to keep microprocessors from overheating and for medical equipment. This is often realized with thermoelectric devices where cooling and heating are performed by special semiconductors. Thermoelectric devices also have the potential for renewable energy, yet cost and efficiency limitations have precluded widespread use. While other semiconductor devices have seen dramatic increases in performance through materials advances, thermoelectric devices still use the same materials as decades ago. This project explores a new pathway to thermoelectrics, taking advantage of recent progress in low-dimensional materials and a novel synthesis technique. This research has the potential for profound impact in many technical areas. The research activities advance knowledge on the control of electrical and thermal transport in two-dimensional semiconductors as well as how to preserve the merit of these materials when they are assembled into bulk forms. The project promotes the education and training of next-generation workforce in semiconductor engineering. These include community-focused, in-person and virtual outreach programs, which serve primarily underprivileged groups on the south side of Chicago.<br/><br/>Technical Description. This research project explores tellurene for thermoelectrics, based on a favorable electronic band structure in its two-dimensional form. A large number of degenerate bands is the key feature for better thermoelectric performance. This activity advances research on similar materials for thermoelectric and other applications. Ligand removal will be systematically studied to minimize interface influence on electrical transport. Carrier density tuning, a challenging problem for 2D semiconductors, will be addressed by a surface doping scheme.The use of inorganic binders allows mild-temperature assembly to preserve nanoscale features. Electrical and thermal transport property characterizations are complemented with Boltzmann transport modeling, which provides deep understanding on the unique features of tellurene. Knowledge generated through this research will provide insights on future materials design for thermoelectric and other device applications.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
