Skip to main content

Thermal and ELectronic Transport in Inorganic-Organic ThermoElectric Superlattices

Periodic Reporting for period 1 - TELIOTES (Thermal and ELectronic Transport in Inorganic-Organic ThermoElectric Superlattices)

Reporting period: 2018-10-01 to 2020-09-30

As the global elderly population increases, further medical attention is required. In turn, this medical demand will require more reliable and energy-efficient medical devices such as therapeutic wraps and blankets. These materials can benefit from flexible wearable thermoelectric materials, which can generate cold or heat from electricity with minimal discomfort on the patient. However, little is known on how deformation and strain affect their efficiency.

Therefore, this project has focused on finding the deformations that increase the thermoelectric efficiency of state-of-the-art materials. These materials are investigated with computer simulations since they have a thickness of a few nanometres, which makes an experimental study much lengthier and more expensive.
This action is important to society because it shows that computer simulations can screen which of the newly-discovered two-dimensional materials have a significant potential to build thermoelectric devices. Subsequently, this project is not only aimed at policymakers and medical doctors to show them the benefits of fundamental research on thermoelectric materials, but also at the scientific community and patent engineers to provide cutting-edge results to guide them in building the next generation of medical devices.
The main work done during this project has been the calculation of the thermal and electronic transport properties of (inorganic) trichalcogenides and (organic) polymers under strain. These materials are studied in their bulk phase and with thicknesses as low as one atomic layer with a number of computer codes. This dimensionality requires the use of quantum-mechanical codes, which offer the maximum precision possible nowadays when predicting, for example, thermal and electronic conductivities.

The main result of this project is that our simulations predict that the compression of trichalcogenides monolayers can double their figure of merit, the key parameter that governs the efficiency of a thermoelectric material. All the results of this project have been published on the journals Nanomaterials, Nano Express, and Nanoscale Advances and disseminated in a number of conferences such as the International Conferences on Thermoelectrics (ICT2019) and the Virtual Conference on thermoelectrics (VCT 2020).
The computational work carried out during this project has advanced the state of the art in the very active fields of strain engineering and thermoelectricity of nanomaterials. The results generated upon the completion of this project has shown that compressions and tensions can be used to increase or decrease several electronic properties of these materials, giving a hint to experimentalist on the route to take when choose materials and designing experiments. This project has also predicted that compressions have the potential to reduce the thermal transport can be reduced by nearly five times, and hence, increasing the thermoelectric efficiency of these materials. This result is paramount for the thermoelectric community given that reducing thermal transport is most effective way to increase the efficiency of the compound. Overall, the results published on how to tune the thermal and electronic properties of these materials are significantly affected by strain can be used to optimise to produce not only more efficient thermoelectric modules, but also optoelectronic devices.