We present a design for tunable directional beaming through a subwavelength metallic double slit surrounded by dielectric surface-relief gratings. On-axis and off-axis beaming can be switched by controlling the incident angle to asymmetrically excite surf
Photoluminescence (PL) conversion of Si nanoparticles by absorbing ultraviolet (UV) lights and emitting visible ones has been used to improve the efficiency of crystalline Si solar cells. Si nanoparticle thin films are prepared by pulverizing porous Si in