Micah Vallin1,2,Michael Pettes1,Richard Zhang2
Los Alamos National Lab1,University of North Texas2
Micah Vallin1,2,Michael Pettes1,Richard Zhang2
Los Alamos National Lab1,University of North Texas2
2D materials have gained more focus in the studies of materials science, often due<br/>to their properties compared to their bulk material counterparts, including a change<br/>in thermal conductivity. These changes in thermal conductivity from bulk materi-<br/>als to 2D materials has prompted investigations into the thermal properties of 2D<br/>materials in order to determine their suitability for applications such as energy sus-<br/>tainability. Because of this interest in 2D materials, there have been efforts to tune<br/>the properties of 2D materials in order to achieve a desired effect for a device; such<br/>tuning efforts methods include doping, adding layers to the 2D material, and strain.<br/>In studying the thermal conductivity of 2D materials, very little work has been done<br/>on the relationship between applied strain and thermal conductivity. This discus-<br/>sion aims to provide a comprehensive review on the effects of strain on the thermal<br/>conductivity of 2D materials using tin diselenide (SnSe2 ) and graphene on a copper<br/>(Cu) substrate. The experiments were performed using a Razorbill UC200 cryogenic<br/>stress-strain instrument in order to induce strain given a voltage input and the ther-<br/>mal conductivity was measured using the optothermal Raman technique while also<br/>taking conduction, radiation, and substrate resistance effects into account. Raman<br/>dependence measurements due to power are measured for every strain voltage in-<br/>put in order to determine the overall shift in thermal conductivity due to induced<br/>strain. The preliminary results for SnSe2 indicate that there is a shift of the Ra-<br/>man power dependence term (χP ) from 0.004 18 cm−1 /µW at no strain induced to<br/>0.003 48 cm−1 /µW at 0.5% strain induced, while preliminary theoretical results for<br/>graphene indicate a shift in the phonon dispersion when a 1% strain is induced to<br/>the unit cell; these indicate that shifts in the thermal conductivity due to strain is<br/>likely large enough to be observable experimentally.