Tunable Absorbers Based on an Electrically Controlled Resistive Layer

Abstract

In this article, an electrically controlled resistive layer (ECRL) is proposed to construct tunable absorbers. This ECRL is composed of VO2 film and resistive layer without lithography pattern. The effective resistance of ECRL is numerically verified to be tuned from 18 to 300 Ω/sq as the VO2 conductivity is changed based on electro-thermally induced insulator-to-metal transition. With such a large tuning range of the effective resistance, the ECRL is utilized to realize a planar tunable bidirectional absorber with absorption efficiency dynamically tuned between 98 and 18% through controlling the conductivity of VO2. In addition, we demonstrate that the ECRL is also suitable for the design of non-planar tunable absorber. It is still found that the ECRL-based tunable absorbers have the wide angle and polarization-insensitive absorbing properties. These results may be of great interest for tunable absorbing, detecting, smart window, and thermo-solar cell applications.