Assessment of the radiative properties of some semi-conductors for applications in thermophotovoltaic and thermophotonic conversion systems

Today, major energy challenge is to find alternatives to exhaustible and polluting fossil fuels. Photovoltaic (PV), thermophotovoltaic (TPV) and thermophotonic (TPX) systems offer interesting prospects for the purpose. However, these technologies require a judicious choice of the emitting materials. This paper presents an assessment of the radiative properties of some semi-conductors that can be used for these systems. The method is based on the principles of thermal radiation, Fresnels theories of radiation, and Maxwells equations describing the classical theory of the propagation of electromagnetic waves in a homogeneous and isotropic medium. The influence of the extinction index on the optical characteristics of some materials (SiC, Si, Ge, and ZnO) is evaluated. The transfer matrix method was used to evaluate and assess the behaviour of the radiative properties of strongly and weakly absorbing multilayered structures. It was found that the use of a non-reflecting treatment (glass or ZnO) on the material, enables to reduce multiple reflections and therefore to improve the efficiency of the system. Keywords: Semi-Conductors; Thermal Radiation; Energy Conversion Systems; Photovoltaic; Thermophotovoltaics; Thermophotonics.