Highly enhanced broadband infrared absorption of germanium by mu...

High-sensitivity and broad bandwidth photo-detector devices are important for both fundamental studies and high-technology applications. Here, by using three-dimensional (3D) finite-difference time-domain simulation, we design an optimized 3D multilayer gold nano-antenna to enhance the nearinfrared (NIR) absorption of germanium nanoparticles. The key ingredient is the simultaneous presence of multiple plasmonic resonance modes with strong light-harvesting effect that encompass a broad bandwidth