Ultrathin continuous silver film for efficient infrared emission

Abstract

An ultrathin silver (Ag) film can behave as an effective medium for enhancing infrared emission due to the tunneling effect and high extinction coefficients in the infrared range. Owing to a fully planar structure, the ultrathin Ag film is free from the complicated fabrication process and is available to practical application. Generally, the infrared emission efficiency of the ultrathin Ag film is deeply affected by film continuity. Herein, by applying plasma treatment and increasing the deposition rate, our work provides an effective solution to fabricating the ultrathin continuous Ag film. Plasma treatment can improve the wetting ability of Ag atoms on substrates and facilitate the lateral growth of Ag film, while high deposition rate can alter the traditional nucleation process. Moreover, the thickness required to obtain an ultrathin continuous Ag film is simultaneously reduced to 5 nm. Additionally, the influence of the ultrathin Ag film on the infrared emission performance of a dielectric-metal-dielectric multilayered infrared emitter is studied. The improvement in continuity and the reduction in thickness of the ultrathin Ag film facilitate the emitter to obtain a desired and efficient infrared emission performance. Our study provides an effective method to fabricate ultrathin continuous Ag film, which enables broadband and highly efficient infrared emission.