Arrays containing carbon nanostructure-oxide-metal diodes, such as carbon nanotube (CNT)-oxide-metal diodes and methods of making and using thereof are described herein. In some embodiments, the arrays contain vertically aligned carbon nanostructures, such as multiwall carbon nanotubes (MWCNTs) coated with a conformal coating of a dielectric layer, such as a metal oxide. The tips of the carbon nanostructures are coated with a low work function metal, such as a calcium or aluminum to form a nanostructure-oxide-metal interface at the tips. The arrays can be used as rectenna at frequencies up to about 40 petahertz because of their intrinsically low capacitance. The arrays described herein produce high asymmetry and non-linearity at low turn on voltages down to 0.3 V and large current densities up to about 7,800 mA/cm.sup.2 and a rectification ratio of at least about 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, or 60.

A photodetection element includes a semiconductor layer having, on one surface side, a periodic concave/convex structure that includes periodic convex portions and concave portions and converts light into surface plasmon, and a metal film provided on the one surface side of the semiconductor layer in correspondence to the periodic concave/convex structure, and in the periodic concave/convex structure, a Schottky junction portion that has a Schottky junction with the metal film is provided on a base end side of the convex portion, and a non-Schottky junction portion that does not have a Schottky junction with the metal film is provided on a distal end side of the convex portion.

A photodetection element includes a semiconductor layer having, on one surface side, a periodic concave/convex structure that includes periodic convex portions and concave portions and converts light into surface plasmon, and a metal film provided on the one surface side of the semiconductor layer in correspondence to the periodic concave/convex structure, and in the periodic concave/convex structure, a Schottky junction portion that has a Schottky junction with the metal film is provided on a base end side of the convex portion, and a non-Schottky junction portion that does not have a Schottky junction with the metal film is provided on a distal end side of the convex portion.

An electricity measuring type surface plasmon resonance sensor including: a plasmon polariton intensifying sensor chip in which a prism and a sensor chip including a transparent electrode, an n-type transparent semiconductor film, and a plasmon resonance film electrode arranged in this order are arranged in an order of the prism, the transparent electrode, the n-type transparent semiconductor film, and the plasmon resonance film electrode; and an electric measuring apparatus which directly measures a current or voltage from the transparent electrode and the plasmon resonance film electrode.

An electricity measuring type surface plasmon resonance sensor including: a plasmon polariton intensifying sensor chip in which a prism and a sensor chip including a transparent electrode, an n-type transparent semiconductor film, and a plasmon resonance film electrode arranged in this order are arranged in an order of the prism, the transparent electrode, the n-type transparent semiconductor film, and the plasmon resonance film electrode; and an electric measuring apparatus which directly measures a current or voltage from the transparent electrode and the plasmon resonance film electrode.

An optoelectronic device, and a method of fabricating an optoelectronic device. The device comprising: a rib waveguide formed of doped silicon, said doped waveguide having a ridge portion, containing an uppermost surface and two sidewall surfaces; and a slab portion, adjacent to the two sidewall surfaces. The device further comprises: a metal contact layer, which directly abuts the uppermost surface and two sidewall surfaces, and which extends along a part of the slab portion so as to provide a Schottky barrier between the metal contact layer and the rib waveguide.

An optoelectronic device, and a method of fabricating an optoelectronic device. The device comprising: a rib waveguide formed of doped silicon, said doped waveguide having a ridge portion, containing an uppermost surface and two sidewall surfaces; and a slab portion, adjacent to the two sidewall surfaces. The device further comprises: a metal contact layer, which directly abuts the uppermost surface and two sidewall surfaces, and which extends along a part of the slab portion so as to provide a Schottky barrier between the metal contact layer and the rib waveguide.

A leaf inspired biomimetic light trapping scheme for ultrathin flexible graphene silicon Schottky junction solar cell. An all-dielectric approach comprising of lossless silica and titania nanoparticles is used for mimicking the two essential light trapping mechanisms of a leaf: (1) focusing and waveguiding and (2) scattering. The light trapping scheme uses two optically tuned layers and does not require any nano-structuring of the active silicon substrate, thereby ensuring that the optical gain is not offset due to recombination losses.

A leaf inspired biomimetic light trapping scheme for ultrathin flexible graphene silicon Schottky junction solar cell. An all-dielectric approach comprising of lossless silica and titania nanoparticles is used for mimicking the two essential light trapping mechanisms of a leaf: (1) focusing and waveguiding and (2) scattering. The light trapping scheme uses two optically tuned layers and does not require any nano-structuring of the active silicon substrate, thereby ensuring that the optical gain is not offset due to recombination losses.

An exemplary photodetector can be provided, which can include, for example, a metal contact, a metal stripe coupled to the metal contact. The semiconductor(s) can surround the metal stripe on at least three sides of the metal stripe. The semiconductor(s) can surround the metal stripe on at least four sides. The semiconductor can surround the metal stripe on at least five sides. A silicon dioxide layer can be coupled to the at least one semiconductor. A graphene layer located can be between the metal stripe and the semiconductor(s).