FI-2015-2-0002: Thermoelectric energy conversion efficiency of conducting polymers

MEC y MICINN

Objectives

The aim of this project is the investigation of the crystal structures of poly-carbazole and pedot
and the possible ways to dope them. In particular, it has been recently proposed that polycarbazole
can be doped by monomer substitution: a monomer of dibenzofuran can replace a carbazole providing a higher level of chargers. Also doping with some simple molecules, like for example FeCl3, provides a good thermoelectric performance. For pedot, the presence of other polymeric chains or of single dopant molecules, have allowed a large increase in its overall figure of merit, especially when considering hole transport. However, for building an efficient device, it would be preferable to have a pedot with good performance with respect to electron transport as well. For both polymers the idea is to find the best dopant, and determine the doping level, to find the optimal configuration to be synthesized in the laboratory.
A key factor here is the doping level. To reach reasonable small level of doping we need to include as many monomers as possible in the polymeric chain. For example, our preliminary investigation pointed out that the simplest unit cell for poly-carbazole contains either 5 or 8 monomers, depending on the mutual angle. With these cells one can then investigate a minimum doping of one dopant versus 5 to 8 monomers, i.e., a doping level between 16 to 20 %. Smaller doping levels do require larger unit cells, and more expensive calculations.

Participants

Roberto D'Agosta
Kaike Yang
Robert Biele