Two-dimensional Tungsten Photonic Crystals as Thermophotovoltaic Selective Emitters

Abstract

In this work we present the design, fabrication and characterization of photonic crystals (PhC) as selective thermal emitters for thermophotovoltaic (TPV) applications. The focus of our investigation is the development of thermal emitters based on two‐dimensional (2D) PhC in single‐crystal tungsten. We show that controlled periodic patterning can be used to fashion selective tungsten emitters that are well‐matched to the photovoltaic (PV) diode of the system. The simulated emittance comparison of flat single‐crystal tungsten and patterned single‐crystal tungsten indicates potential for nearly doubling the TPV system efficiency. Measured results of a fabricated prototype structure correspond well to the simulated values. The fabrication is accomplished using laser interference lithography and reactive ion etching, the benefits and parameters of which are presented.