A Highly Efficient, Selective and Thermally‐Stable Dielectric Multilayer Emitter for Solar Thermophotovoltaics

This paper presents the design, optimization, fabrication, and characterization of a highly‐efficient Selective Emitter (SE) for solar thermophotovoltaic systems. An SE consisting of three layers (SiNx ‐ SiO2 ‐ TiO2) deposited on a tungsten substrate is optimized for use with PV cells based on III‐V semiconductors, such as GaSb, InGaAs, and InGaAsSb. The fabricated SE shows an emitter efficiency (ηSE) of 50% when coupled with a PV cell having an energy bandgap of 0.63 eV. After a thermal treatment carried out at 1000∘C for 8 hours in a vacuum environment, an ηSE of 46% is recorded, demonstrating the thermal stability of the proposed SE. Its behavior at high temperatures has also been studied using simulations based on the transfer matrix method and on refractive indices experimentally measured at different temperatures (up to 1000∘C). The results show an ηSE of 44% in the energy bandgap range of 0.55 to 0.63 eV, proving that the proposed structure is promising and can operate at high temperatures. In addition, the behavior of a real PV cell has been simulated, and calculations show a maximum PV cell efficiency of 15% at 1000∘C and 25% at 1600∘C, exceeding the Shockley‐Queisser limit.This article is protected by copyright. All rights reserved.