We report the numerical study of a selective thermal emitter based on a metallic multilayered structure consisting of a graded antireflection top layer, a middle layer with uniform porosity (i.e., volume fraction of voids), and a nonporous substrate layer. Simulation results show that the proposed emitters feature an emission edge in near-IR where the emissivity drops from over 0.9 to below 0.1, for both the TE and TM polarizations. Moreover, these desired emission characteristics persist for a wide range of emission angles with the emission edge nearly nonshifted, making the proposed emitters promising for achieving isotropic thermal emission. The designed emitters are particularly attractive for the thermal-photovoltaic applications by suppressing emission below the photovoltaic material bandgap, which is normally in near-IR.
© 2012 Optical Society of America
Original Manuscript: August 2, 2012
Revised Manuscript: September 28, 2012
Manuscript Accepted: October 16, 2012
Published: November 27, 2012
Shiwei Shu, Lingxia Zheng, Hui Li, Chun Kwan Tsang, Liange Shi, and Yang Yang Li, "Porous metal-based multilayers for selective thermal emitters," Opt. Lett. 37, 4883-4885 (2012)