America Castaneda

Major: Electrical Engineering and Computer Science
Mentors: Somaiyeh Shokri-Kalan, William Huynh, Professor Susanne Stemme

ON-CHIP THERMOELECTRIC MEASUREMENTS OF CADMIUM ARSENIDE THIN FILMS

Thermoelectrics, which involve the conversion of heat energy into electrical energy, reveal fundamental insights into a material's electronic properties. In this study, we focus on measuring the thermoelectric properties of Cadmium Arsenide thin films using on-chip techniques. I have programmed and analyzed various data plots, including reciprocal space maps and Seebeck measurements performed at a temperature of 15K. The reciprocal space maps are instrumental in examining the film’s topography, helping us to identify prominent peaks and evaluate mosaicity, which provides insights into the film’s structural quality and uniformity. We also investigated how the Seebeck voltage responds to changes in temperature gradient, gate voltage, and magnetic fields. Our thermal calibration process allowed us to accurately induce and measure temperature gradients, confirming that the observed Seebeck effect is thermoelectric in origin. Additionally, gate voltage sweeps at high magnetic fields revealed peaks in the Seebeck voltage associated with maximum entropy at the center of each Landau level. Our results suggest that two-dimensional Cadmium Arsenide thin films hold significant potential for cryogenic applications and require further study.