We present a numerical study on a 2D array of plasmonic structures covered by a subwavelength film. We explain the origin of surface lattice resonances (SLRs) using the coupled dipole approximation and show that the diffraction-assisted plasmonic resonances and formation of bound states in the continuum (BICs) can be controlled by altering the optical environment. Our study shows that when the refractive index contrast Δn < −0.1, the SLR cannot be excited, while a significant contrast (Δn > 0.3) not only sustains plasmonic-induced resonances but also forms both symmetry-protected and accidental BICs. The results can aid the streamlined design of plasmonic lattices in studies on light–matter interactions and applications in biosensors and optoelectronic devices.
Solar-to-steam (STS) generation based on plasmonic materials has attracted significant attention as a green method for producing fresh water. Herein, a simple in situ method is introduced to fabricate Au nanoparticles (AuNPs) on cellulose filter papers as dual-functional substrates for STS generation and surface-enhanced Raman spectroscopy (SERS) sensing. The substrates exhibit 90% of broadband solar absorption between 350 and 1800 nm and achieve an evaporation rate of 0.96 kg·m−2·h−1 under 1-sun illumination, room temperature of 20 °C, and relative humidity of 40%. The STS generation of the substrate is stable during 30 h continuous operation. Enriched SERS hotspots between AuNPs endow the substrates with the ability to detect chemical contamination in water with ppb limits of detection for rhodamine 6G dye and melamine. To demonstrate dual-functional properties, the contaminated water was analyzed with SERS and purified by STS. The purified water was then analyzed with SERS to confirm its purity. The developed substrate can be an improved and suitable candidate for fresh water production and qualification.
Owing to their high oscillator strength, binding energy, and low-cost fabrication, two-dimensional halide perovskites have recently gained attention as excellent materials for generating exciton-polaritons at room temperature. Unlike traditional materials used for polaritons, such as ZnO, GaAs, and GaN, halide perovskites exhibit great compatibility with matured CMOS technologies. However, no studies have reported perovskite-based polaritons on silicon platforms. Here, we numerically demonstrate the possibility of a polariton when a Si nanodisk array couples with a thin film of phenethylammonium lead iodide perovskite. An asymmetric lattice of thin Si nanodisks is used to generate surface lattice resonances from the coupling between the disk's electrical resonator and the lattice's diffracted waves. Polaritonic modes with high Rabi splitting values can be easily achieved for a large range of parameters. This Rabi splitting can be engineered by varying the ratio of electromagnetic energy confined within the Si disk and perovskite thin film. This study provides insight into nanophotonic structure design for CMOS-based optoelectronics, sensors, and polaritonic devices.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.