Reflectance spectral studies of spark plasma sintered tungsten carbide pellet

TL;DR

This study presents the first spectral reflectance measurements of tungsten carbide prepared via spark plasma sintering, demonstrating its potential as a solar selective absorber due to its low-energy plasma excitation.

Contribution

It introduces a novel optical measurement system and provides the first spectral reflectance data for WC, linking experimental results with ab initio calculations.

Findings

Spectral reflectance shows a low-energy plasma excitation at 0.6 eV.

WC's spectral properties align with solar absorption requirements.

Sample quality influences spectral reflectance characteristics.

Abstract

We report the first spectral reflectance of tungsten carbide (WC) as potential solar selective absorber. We developed an optical measurement system for visible to mid-infrared spectroscopy, covering the range of 0.1 to 2.5 eV, to evaluate the solar selectivity. A polycrystalline WC was prepared using spark plasma sintering method. The measured spectral reflectance of WC exhibits a low-energy plasma excitation around 0.6 eV corresponding to the cutoff energy of sunlight, consistent with ab initio calculations, thus making it preferable for the solar selective absorber. We also discuss effects of the sample quality on the spectral reflectance.