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Solar energy is widely considered a "green energy" source, and to maximize its utilization, efficient solar absorbers that can absorb solar energy at various optical frequencies are necessary. In this study, we report a high-performance, broadband solar absorber made of just two materials – tungsten(W) and Al2O3. The absorber is composed of three layers, arranged from top to bottom: an Al2O3 dielectric layer, a W hole-mesh layer, and a W substrate layer. Finite time domain(FDTD) analysis simulations demonstrated an ultra-high absorption rate of 97.64% across a wide spectrum of visible and near-infrared light (400nm-1600nm). The high absorption rate is attributed to the combined effects of surface plasmon resonance, cavity resonance, and the high imaginary part of the permittivity of tungsten. Furthermore, we analyzed the influence of the geometric parameters of the W hole-mesh absorber on the absorption performance and explained the physical mechanism of the high absorption rate by analyzing impedance matching. Interestingly, the absorber is insensitive to polarized light and can still maintain a high absorption rate of 90% at an incident angle of 0-60°. Our findings indicate that the W hole-mesh absorber has significant advantages in solar energy harvesting, paving the way for more efficient and cost-effective solar energy technology.

A series of ionic and neutral alcohol soluble Cu(I) complexes were obtained by reaction of 2-(pentafluorophenyl)-1H-imidazo[4,5-f][1,10]-phenanthroline (ppipH), [Cu(MeCN)4]ClO4 and the chelating diphosphine ligands bis[(2-diphenylphosphino)phenyl]ether (POP), 4,6-bis(diphenylphosphino)phenoxazine (nixantphos), 9,9-dimethyl-4,5-bis(diphenylphosphino)-9H-xanthene (xantphos) and (±)-2,2′-bis(diphenylphosphino)-1,1′-binaphthalene (BINAP) in neutral and strong alkaline media, respectively. Most complexes display moderate to intense luminescence in the solid state and weak, negligible luminescence in EtOH solutions. The aggregation-induced emission for the Cu(I) complexes of flexible POP ligands in ethanol/water system was studied.

Considerable attention has been focused on Cu(i)-diimine-phosphine complexes because of their good room-temperature phosphorescence since 1979, but no attention has been focused on the exploration and exploitation by using them as smart acid-base responsive switching luminescent materials. Herein, the reaction of [Cu(MeCN)4]PF6, 2-(2-naphthyl)-1H-imidazo[4,5-f][1,10]phenanthroline (nimpH) and chelating diphosphine ligands bis[(2-diphenylphosphino)phenyl] ether (POP) and 9,9-dimethyl-4,5-bis(diphenylphosphino)-9H-xanthene (xantphos) or (±)-2,2'-bis(diphenylphosphino)-1,1'-binaphthalene (BINAP) in a 1 : 1 : 1 ratio afforded three ionic [Cu(nimpH)(PP)]PF6 complexes (PP = POP, 1a; xantphos, 2a; BINAP, 3a) and three neutral [Cu(nimp)(PP)] complexes (PP = POP, 1b; xantphos, 2b; BINAP, 3b) in neutral and strong alkaline media, respectively. The non-emissive complexes 1a, 2a and 3a exhibit turn-on luminescence upon exposure to the strong base NaOH and tetrabutylammonium fluoride (TBAF), and the intensely emissive complexes 1b, 2b and 3b display turn-off luminescence upon exposure to trifluoroacetic acid (TFA) in CH2Cl2 solutions. Naked-eye repeatable off-on-off or on-off-on luminescence behaviors of these complexes are observed in CH2Cl2 with reversible base-acid or acid-base responses. On the other hand, the addition of TBAF to neutral complexes 1b, 2b and 3b results in obvious luminescence enhancement, especially for the diluted solutions and complexes with the flexible diphosphine ligand POP. The plausible mechanisms of the above results are discussed.

Aiming at wearable electronic equipment in wireless body area network communication, we propose a circularly polarized wearable antenna based on artificial magnetic conductor (AMC) for the problem of unreliable data transmission of linearly polarized wearable antenna and reduction of transmission distance due to the low gain of antenna. The AMC of in-phase reflection reflects the backward radiation to the top to reduce the damage of the antenna to human body. And the polarization direction of the reflected wave reflected through AMC is the same as that of the main direction, which makes the radiation performance of the antenna improved. Meanwhile, the antenna is flexible and lightweight due to the use of flexible polyimide and graphene films as the substrate and conductor materials. The antenna was also simulated and the prototype was fabricated and tested. The simulation results show that the working bandwidth covers 2.4–2.48 GHz, and the peak gain is 8.09 dBi. The peak specific absorption rate of 1 g and 10 g of human tissue at an input power of 350 mW is 1.48 W kg−1 and 0.65 W kg−1, respectively, which meets the safety standards.