Development of Emitter with High Light Absorptivity and Low Emissivity for Thermionic Energy Converter Driven by Solar Light

Abstract

In order to increase an energy conversion efficiency of “Solar TEC” which is a thermionic energy converter driven by the solar light, the emitter should absorb the solar light with high rate. In the present paper, the emitter with light trap is proposed and the effective absorptivity α_eff is numerically estimated. It is found that α_eff is remarkably increased from 0.3 to 0.92 by adjusting the angle of a cone which is equipped inside the light trap to improve α_eff, while an emissivity of the emitter ε remains original value. Moreover, the method to obtain α_eff and ε experimentally was introduced.