Abstract
Due to their structured density of states, molecular junctions provide rich resources to filter and control the flow of electrons and phonons. Here we compute the out of equilibrium current-voltage characteristics and dissipated heat of some recently synthesized oligophenylenes (OPE3) using the Density Functional based Tight-Binding (DFTB) method within Non-Equilibrium Green's Function Theory (NEGF). We analyze the Peltier cooling power for these molecular junctions as function of a bias voltage and investigate the parameters that lead to optimal cooling performance. In order to quantify the attainable temperature reduction, an electro-thermal circuit model is presented, in which the key electronic and thermal transport parameters enter. Overall, our results demonstrate that the studied OPE3 devices are compatible with temperature reductions of several K. Based on the results, some strategies to enable high performance devices for cooling applications are briefly discussed.
| Original language | English |
|---|---|
| Article number | 11003 |
| Number of pages | 9 |
| Journal | Nanoscale |
| Volume | 14 |
| Issue number | 30 |
| DOIs | |
| Publication status | Published - 14 Jul 2022 |
| MoE publication type | A1 Journal article-refereed |
Funding
We acknowledge the European Commission H2020 projects ‘EFINED’ http://www.efined-h2020.eu Grant Agreement No. 766853 for providing financial resources to our project. We thank the GENCI for computational resources (under project DARI A0050810637 and A0070810637). MP acknowledges financial support of the Academy of Finland through project HyPhEN (No. 342586) and Centre of Excellence Program No. 336817. TAN would like to thank Alessandro Pecchia for advice and access to the gdftb code. We thank the EFINED team for inspiring discussions.