Part of the book: Application of Solar Energy
Graphene is a ground‐breaking two‐dimensional (2D) material that possesses outstanding electrical, optical, thermal, and mechanical properties and that promises a new generation of devices. Despite all these, some applications require graphene‐based materials with different characteristics, such as good solubility in organic solvents and a specific band gap to be dispersible in polymer nanocomposite matrix and applied as active layer, electron transport layer (ETL) or hole transport layer (HTL) in organic photovoltaics. Chemically modified graphene derivatives are studied, searching for better dispersions and even more properties for different applications. Most of the attention has been drawn to dispersions of graphene oxides or highly reduced graphene oxides. Therefore, this allows an opportunity to study the characteristics of materials with intermediate oxidation degrees and its applications.
Part of the book: Graphene Materials
In this chapter, the impact of the shape of thermoelectric legs and parasitic contact resistances from metal electrodes and device wiring on thermoelectric figure of merit ZT is addressed. First section deals with the influence of the legs geometry on ZT. The shape of the legs is crucial in the thermoelectric performance of the thermoelectric devices. Unlike to conventional geometry thermoelectric legs, non-constant cross-section legs could help by lowering the overall thermal conductance of the device so as to increase the temperature gradient along legs, hence harnessing the Thomson effect, which is generally neglected in constant square cross-section thermoelectric legs. The final section is devoted to the electrical contact engineering of the device. Parasitic contact and wiring resistances play an important role in the performance of the device because they increase the isothermal resistance of the device. As the isothermal resistance of the device increases, the ZT decreases.
Part of the book: Bringing Thermoelectricity into Reality