Plasmonic nanostructures for organic image sensors

An optical sensor, comprising:

• a first electrode disposed over a semiconductor substrate;
• a photoelectrical conversion element, which includes a p-type layer and an n-type layer, arranged over the first electrode to convert one or more photons having wavelength falling within a predetermined wavelength range into an electrical signal;
• and
• a second electrode disposed over the photoelectrical conversion element, wherein the second electrode is transparent in the predetermined wavelength range;
• wherein the first and second electrodes are each made up of plasmonic nanostructures.

An optical sensor, comprising:

• an array of photoelectrical conversion elements arranged over a semiconductor substrate;
• an array of plasmonic color filters arranged over the array of photoelectrical conversion elements, wherein respective plasmonic color filters are arranged over respective photoelectrical conversion elements;
• and
• a sidewall reflector arranged about a perimeter of a photoelectrical conversion element and arranged to reflect light back towards the photoelectrical conversion element, wherein the sidewall reflector includes a metal core with a dielectric coating on at least one sidewall thereof.