Near‐Perfect Ultrathin Nanocomposite Absorber with Self‐Formed Topping Plasmonic Nanoparticles

Abstract

Nanocomposites, consisting of metallic nanoparticles embedding in a dielectric host, can significantly enhance light–matter interactions in solar energy conversion and optical applications. In this contribution, a class of scalable ultrathin nanocomposite films with self‐formed topping plasmonic nanoparticles is proposed. Just by controlling the high‐throughput co‐sputtering process, the nanocomposite absorbers can achieve near 100% light absorption in the wavelength ranges from 300 to 800 nm. Through systematic experiments and numerical studies, three mechanisms for this near‐perfect absorption are further revealed: impedance matching of ultrathin nanocomposite film with tunable filling factor, excitation of localized surface plasmon induced by self‐formed topping nanoparticles, and near‐field coupling between the topping nanoparticles and bottom metallic reflective layer. With these merits, the proposed ultrathin nanocomposite absorbers have demonstrated their outstanding omnidirectional absorptance over the wide solar irradiance spectrum ranging from 250 to 2000 nm.

Novel Receiver-Enhanced Solar Vapor Generation: Review and Perspectives

“…Lu et al, fabricated scalable ultrathin nanocomposite films with self-formed topping plasmonic nanoparticles to achieve near perfect light absorption in the wavelength ranges from visible to near-infrared regions. The simulation results show that Ag topping nanoparticles enhance the light absorption of the nanocomposite absorber in the visible range as in Figure 5e,f [72]. [72].…”

“…The simulation results show that Ag topping nanoparticles enhance the light absorption of the nanocomposite absorber in the visible range as in Figure 5e,f [72]. [72]. Reprinted with permission from [72].…”

“…[72]. Reprinted with permission from [72]. Copyright (2017) WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.…”

“…The absorbed solar energy, thermal emission, and convection heat transfer determine the temperature of the absorber in the equilibrium state, as described by the Equation (1): , and 100 nm of periodicity, respectively [72]. Reprinted with permission from [72].…”

“…By following the Equation (1), a solar absorber can achieve high temperature by maximizing the solar absorptance while keeping low thermal radiation and low heat convection. Typical spectrally selective solar absorbers, such as cermet absorbers and lithography-free ultrathin multilayer absorbers, are designed to have a perfect cutoff wavelength, as shown in Figure 6a, which avoids the absorption band in the blackbody radiation distribution [72]. However, it is more realistic to consider the absorption tailored near zero in the longer wavelength ranges [75].…”