Amalya Johnson
TomKat Graduate Fellow for Translational Research
Research Lab: Fang Liu
Year Awarded: 2023
Amalya is a PhD candidate in the department of Materials Science and Engineering. She received her undergraduate degree in Physics from Columbia University, where she also received a minor in Women’s and Gender Studies and was captain of the Women’s Soccer Team. At Stanford, Amalya studies the thermal, structural, and excitonic properties of atomically thin semiconductors under Professor Fang Liu, and develops new fabrication procedures for high-quality, large-area production of these materials. She is primarily interested in creating new ways to tune and understand the properties of these materials for advanced energy conversion and microelectronic applications.
Scalable Morphology Engineering of 2D Materials for Thermoelectric Applications
As the global energy demand rapidly increases, developing energy efficient and sustainable energy sources will play a key role in mitigating the climate crisis. Thermoelectric (TE) devices are a promising source of clean energy as they can convert thermal energy from waste heat, which comprises 72% of global energy generated, back into electric power. Expanding the availability of TE devices and applying them to existing waste heat sources such as motors, hot water pipes, industrial equipment, computer servers, and more, can help significantly increase global production of and access to sustainable energy.
Recently, Two-Dimensional (2D) materials such as monolayer transition metal dichalcogenides (TMDs), graphene, and SnSe have garnered interest for TE applications due to their low thermal conductivities, high and tunable Seebeck coefficients, tunable electrical conductivities, and relative affordability. In this project, we aim to tune the electrical and thermal conductivities of 2D materials through morphology engineering. Morphology engineering, which refers to the design and creation of nanometer sized bubbles or wrinkles, has a great potential to modulate the heat exchange, thermal insulation, and energy conversion properties of 2D materials. Our group has devised a lithography-free technique to engineer periodic nanoscale bubbles and wrinkles into monolayer materials. This designer approach can be used to control and realize new thermoelectric properties in a variety of thin materials, by controllably manipulating phonon and electron transport characteristics. The technique can be scaled for large scale production and commercialization, and will lead to the development of low-cost, flexible sustainable energy converters with the potential to be applied to a wide range of waste heat sources.