Simulation and Modelling of Organic Thermoelectric Materials and Devices
Giới thiệu về sách điện tử này
This thesis employs multi-scale computational modeling to advance the understanding and optimization of organic thermoelectric materials and devices, including: (I) Finite element method modeling to analyze and optimize the micro-TEGs, (II) Ab initio molecular dynamics simulations to investigate charge transport mechanisms in PEDOT conducting polymer, and (III) Machine learning approaches to predict and study the electronic properties of PEDOT thin films.
Part (I) presents that achieving power densities in the range of mW cm−2 at a temperature gradient of 10 K is feasible through geometrical optimization and utilizing advanced organic thermoelectric inks. Particularly, we simulated the PEDOT:PSS/BBL:PEI micro-TEGs and improved device efficiency under varying thermal gradients using COMSOL software.
In part (II), we developed a computational technique based on ab initio molecular dynamics to trace the temporal motion of charge carriers in a single PEDOT chain and in coupled chains with varying degrees of interaction. Subsequently, we used ab initio molecular dynamics to demonstrate that charge transport along the chains is band-like, while transport across chains follows a hopping-like mechanism. The calculated polaron mobility along the chains reached 4 cm2V−1s−1, providing a theoretical upper limit for thiophene-based conducting polymers. Also, we quantified the hopping rate between chains, consistent with Marcus theory, by analyzing polaron jumps.
Part (III) integrates computational modeling with machine learning to explore changes in morphological and transport properties of PEDOT:Tos prepared using different solvents. We employed convolutional neural networks to achieve high accuracy (r2>0.99) in predicting electronic coupling values and significantly accelerated the analysis compared to density functional theory calculations. This approach enabled detailed investigations into how different solvents affect the electronic coupling of PEDOT dimers.
We believe that our findings on organic thermoelectric material and devices provide a comprehensive framework for improving the performance and scalability of organic TEGs and open new avenues for further research.
