Hot electron-enabled novel detection functionalities.
(A) Left: Schematic of hot electron nanoscopy. The gold taper adiabatically compresses the SPPs, providing hot electrons with momentum perpendicular to the semiconductor surface. Right: Hot electron map generated by the nanotaper. (B) Left: Schematic of a circularly polarized light detector combining a silver chiral metamaterial and silicon. Right: Experimentally measured responsivity spectrum for left and right hand circularly polarized light. (C) Left: Narrowband responsivity spectrum of a plasmonic grating-based hot electron detector. Right: The responsivity peak position shows a linear dependence on the interslit distance. (D) Left: Schematic of a MIM diode for wavelength determination. Right: Photocurrent under bias and 808 nm illumination at different powers showing constant open-circuit voltages. Figures adapted with permission from: (A) Ref. , ©2013 Nature Publishing Group; (B) Ref. , ©2015 Nature Publishing Group; (C) Ref. , ©2013 Nature Publishing Group; (D) Ref. , ©2013 Nature Publishing Group.