Thermoelectric transport through a zigzag like chain: Influence of the chain length, the interdot tunneling and the intradot Coulomb interaction

We have studied the thermoelectric transport through a zigzaglike chain in the linear response regime using the non-equilibrium Green's function method. This model consists of the main zigzaglike chain and the side radicals coupled with the main chain at the next-near-neighbor sites. The finite-scale effect on the thermoelectric properties has been studied, our results show that thermoelectric efficiency can be enhanced by increasing the chain length. The thermopower and the figure of merit can be enhanced by strengthening the interdot tunneling coupling between the main chain and the side radicals. However, increase of the interdot tunneling coupling in the main chain can weaken the thermoelectric efficiency. Moreover, the thermoelectric efficiency is also strongly dependent on the intradot Coulomb interaction. These results can provide a guidance for the synthesis of thermal devices with high thermoelectric efficiency.