Thermoelectric Properties of a p-n Module Based on TTT2I3 and TTT(TCNQ)2 Organic Crystals

Abstract

In this paper the thermoelectric properties of p – n thermoelectric module of organic nanostructured crystals is investigated. A thermoelectric module (TM) is a device designed for direct conversion of heat to electricity or for cooling effect by applying a small electrical current at the pairs legs. TMs are embedded in a various of devices: thermal generators for energy harvesting at industrial scale, personalized mini devices for power generation or local cooling effect for integrated circuits. In modern medical devices, TMs are used for accurate temperature control in PCR (polymerase chain reaction), biological samples and vaccines transportation, continuous temperature monitoring and others. However, most commercialized TMs nowadays are made of inorganic compounds with a low rate of energy conversion. By the other side, organic materials are more reliable, flexible with a higher efficiency at low temperature gradients. Earlier, it was established theoretically that organic crystals of TTT2I3 of p – type and TTT(TCNQ)2 of n – type are very prospective materials for thermoelectric applications at near-to-room temperature. For temperatures not exceeding ~ 400 K, it is expected that crystals properties will not change significantly. The charge transport and thermoelectric properties are predicted to significantly enhance by some manipulations with carrier and impurity concentrations. In the following, the electrical conductivity, the output voltage, and the maximum power factor of a p-n module made of these crystals is calculated numerically for different combinations of crystals parameters and temperature gradients.