A new level of anisotropic plasmonic laser printing for aluminum multifunctional metasurfaces.

Emerging high-index all-dielectric nanostructures, capable of manipulating light on the subwavelength scale, empower designing and implementing novel antireflection and light-trapping layers in many photonic and optoelectronic devices. However, their performance and practicality are compromised by relatively narrow bandwidths and highly sophisticated fabrications. In this paper, we demonstrate an ultra-broadband (300-1200 nm) directional light scattering strategy using high-index surface silicon oligomer resonators fabricated by a facile, scalable, and low-cost colloidal lithography technique. The exceptional broadband forward scattering stems from a combined effect of strongly intercoupled Mie resonances within the oligomers composed of randomly positioned nanodisks in the visible region and a strong electric mode coupling between the oligomers and the high-index substrate in the red-to-near-infrared region. By implementing this efficient approach in silicon solar cells, the integrated optical reflection loss across the wavelength range 300-1200 nm can be as low as 7%. Consequently, the short-circuit current density determined from the external quantum efficiency of solar cells can be increased to 35.1 from 25.1 mA/cm, representing an enhancement of 40%, with a demonstrated energy conversion efficiency exceeding 15.0%. The insights in this paper hold great potentials for new classes of light management and steering photonic devices with drastically improved practicality.

No abstract

Hot electron intraband luminescence from plasmonic nanostructures is of critical importance for integrated photonic devices and applications in ultracompact nanospectrometer, bioimaging, information encryption et al. Although, the past few decades have witnessed tremendous progress in enhancing the luminescence efficiency of plasmonic nanostructures, the luminescence is usually unpolarized or partially polarized and difficult to be tailored because of its incoherent and broadband feature, significantly limiting its applications. Here the current limitation, demonstrating extremely polarized hot electron intraband luminescence with record‐high degree of linear polarization (≈1) and ≈40 000‐fold enhancement from judiciously designed aluminium (Al) plasmonic nanostructures, is broken through. The designed nanostructures exhibit strong polarization‐dependent anisotropic scattering across the visible band which efficiently modulates the luminescence in orthogonal directions. Leveraging this appealing feature, high‐contrast analyzer controlled optical image encryption and camouflage for information security applications are demonstrated. This research lays the groundwork for integrated nonlinear photonic devices based on complementary metal–oxide–semiconductor (CMOS)‐compatible plasmonic materials and paves the way for ultracompact on‐chip photonic devices demanding polarized white light sources.

No abstract