Large Thermopower, Crystalline Cd3As2 by Low-Temperature Vapor Deposition for Room Temperature Heat Waste Recovery
Mentor 1
Nikolia Kouklin
Location
Union Wisconsin Room
Start Date
28-4-2017 1:30 PM
End Date
28-4-2017 4:00 PM
Description
Cadmium Arsenide (Cd3As2) is a topological Dirac semimetal which is known as the 3D analogue of graphene and exhibits one of the largest electron mobilities in crystalline materials. The backscattering of carriers remains suppressed and the electrical transport is dominated by high-energy carriers that favorably affect the thermopower of Cd3As2. Thermoelectric generators convert thermal energy into electric energy and are prime candidates for recovering lost thermal energy back into usable electric energy. In this experiment, thermoelectric generators were built using crystalline Cd3As2 platelets grown by low temperature vapor deposition. The Cd3As2 platelets were examined by scanning electron microscopy to obtain images, energy dispersive X-ray spectroscopy to confirm the stoichiometry of the sample, and Raman spectroscopy to determine the sample quality. The thermoelectric generators were then built using the platelets across two electrodes and temperature dependent current voltage characteristics were measured resulting in an Ohmic-like transport behavior. The Seebeck coefficient was then measured under temperature dependence to assess the thermopower of the platelets. The measured high room-temperature thermopowers of up to 613 uVK^-1 identify Cd3As2 as a promising thermoelectric material for low temperature thermoelectric generators.
Large Thermopower, Crystalline Cd3As2 by Low-Temperature Vapor Deposition for Room Temperature Heat Waste Recovery
Union Wisconsin Room
Cadmium Arsenide (Cd3As2) is a topological Dirac semimetal which is known as the 3D analogue of graphene and exhibits one of the largest electron mobilities in crystalline materials. The backscattering of carriers remains suppressed and the electrical transport is dominated by high-energy carriers that favorably affect the thermopower of Cd3As2. Thermoelectric generators convert thermal energy into electric energy and are prime candidates for recovering lost thermal energy back into usable electric energy. In this experiment, thermoelectric generators were built using crystalline Cd3As2 platelets grown by low temperature vapor deposition. The Cd3As2 platelets were examined by scanning electron microscopy to obtain images, energy dispersive X-ray spectroscopy to confirm the stoichiometry of the sample, and Raman spectroscopy to determine the sample quality. The thermoelectric generators were then built using the platelets across two electrodes and temperature dependent current voltage characteristics were measured resulting in an Ohmic-like transport behavior. The Seebeck coefficient was then measured under temperature dependence to assess the thermopower of the platelets. The measured high room-temperature thermopowers of up to 613 uVK^-1 identify Cd3As2 as a promising thermoelectric material for low temperature thermoelectric generators.
