Thermoelectrics

Building up a solid-state material from quantum dots (QDs), often referred to as artificial atoms, offers the potential to create new materials with tunable macroscopic properties. In recent years, investigating the electronic properties of such QD assemblies has gained significant attention due to their increasing applications electronics and optoelectronics. QD assemblies are often regarded as highly disordered materials with localized energy states through which the charge transports via thermally assisted tunneling. The theoretical framework of the charge transport in nanoparticles was established long ago and it might fall short on accounting for some of the new emerging properties of the QD solids. In this project we study the charge transport of the QDs with different ligand lengths, size distributions and compositions. Additionally, we investigate the thermoelectric properties of the QD solids for potential applications in hybrid organic/inorganic thermoelectric materials. 

Contact: Morteza Shokrani

In order to use organic semiconductors for various applications in the field of electronics and photovoltaics, it is crucial to have a better understanding of the underlying charge transport mechanisms. Most current models rely on tunnelling (hopping) of charge carriers between localized states, where the rate is among others determined by their spatial and energy separation. Usually, these hopping processes are investigated numerically, but in this project, we utilize micrometer scale interdigitate electrodes to achieve high electric fields in order to get a better understanding of the localization length in organic semiconductors.

Contact: Felix Graf

The field of thermoelectric energy conversion has held great promise to convert heat to electrical power, using a technology that is free of moving parts and thereby silent and extremely durable. The objectives are (i) to describe electronic charge and heat transport in disordered, partially ordered and hybrid systems using kinetic Monte-Carlo calculations of hopping transport, and (ii) to provide recommendations for material selection and device design for especiallypolycrystalline and hybrid systems. Hybrid and organic materials provide an excellent alternative to inorganic counterparts with rare and/or toxic elements which are brittle and require energy-intensive fabrication processes.

This project is part of the MSCA ITN HORATES.

Contact: Aditya Dash

On paper, ‘heat’ is an extremely abundant source of energy, being available as waste product and as part of the solar spectrum. Unfortunately, converting heat to useful electrical power is far from trivial. We pursue doped hybrid and organic materials for use as low-cost, eco-friendly active layers in printable thermoelectric generators. Through experiments and modeling we try to exploit the inherently low thermal conductivity of organic (semi)conductors while boosting the electrical conductivity and thermopower.

Contact: Morteza Shokrani

In this project the thermoelectric properties of organic semiconductors using kinetic Monte Carlo (kMC) models that incorporate morphologies derived from molecular dynamics (MD) simulations are explored. A focus is examining localization distributions resulting from the molecular structures of these materials. By integrating kMC models with MD-based morphologies, we gain deeper insights into the transport mechanisms and efficiencies of organic semiconductors, contributing to the optimization of thermoelectric properties and the development of more efficient materials.

Contact: Dennis Derewjanko