Techniques for enhancing the absorption of photons in semiconductors with the use of microstructures are described. The microstructures, such as pillars and/or holes, effectively increase the effective absorption length resulting in a greater absorption of the photons. Using microstructures for absorption enhancement for silicon photodiodes and silicon avalanche photodiodes can result in bandwidths in excess of 10 Gb/s at photons with wavelengths of 850 nm, and with quantum efficiencies of approximately 90% or more.

A photodetector includes a metal layer that shields incident light and generates surface plasmon polaritons (SPPs), a light absorbing layer that absorbs the generated SPPs and allows charges excited by the absorbed SPPs and a localized electric field effect to tunnel, a dielectric formed at nanoholes in which at least a part of the metal layer is opened, and a semiconductor layer that induces the photocurrent based on an electric field effect of tunneled electrons. The SPPs form localized surface plasmons (LSPs) at an interface where the metal layer meets the dielectric.

This electromagnetic wave detector that detects electromagnetic waves by performing photoelectric conversion includes: a substrate; an insulating layer that is provided on the substrate; a graphene layer that is provided on the insulating layer; a pair of electrodes, which are provided on the insulating layer, and which are connected to both ends of the graphene layer, respectively; and a contact layer that is provided such that the contact layer is in contact with the graphene layer. The contact layer is formed of a material having a polar group, and a charge is formed in the graphene layer by having the contact layer in contact with the graphene layer.

An electromagnetic wave detector includes: an insulating film having a first surface and a second surface facing the first surface; a first layer to perform photoelectric conversion by an incident electromagnetic wave and change in potential, the first layer being made of a first two-dimensional atomic layer material; and a second layer to receive the change in potential through the first insulating film and generate change in electrical quantity, the second layer being made of a second two-dimensional atomic layer material and provided on the first surface. In this manner, the sensitive electromagnetic wave detector detecting an incident electromagnetic wave as change in electrical quantity and having high response speed to an incident electromagnetic wave can be provided.

The present disclosure provides a two-dimensional material detector with an asymmetrically integrated optical microstrip antenna, structurally including a metal reflecting surface, a dielectric spacer layer, a two-dimensional active material layer, a top source electrode, and a drain electrode integrated with a metal strip array. Self-driven photoresponse of a metal/two-dimensional material/metal structure is induced by a Schottky junction formed due to contact between the two-dimensional material and the metal. The asymmetrically integrated optical microstrip antennas break the symmetry between the two contact/two-dimensional material junctions. Light absorption in the contact/two-dimensional material junction integrated with optical patch antennas is significantly enhanced by efficient light in-coupling and intensified light localization; meanwhile, the extended boundary of the contact/two-dimensional material junction enlarges the photocurrent collection area. The light absorption in the other contact/two-dimensional material junction is significantly inhibited by a metal bottom surface which is very close to the two-dimensional material.

A plasmonic field-enhanced photodetector is disclosed. The photodetector absorbs surface plasmon polaritons (SPPs) by using a light absorbing layer having a conduction band and a valence band in which an energy is split, the SPPs being generated by combining surface plasmons (SPs) with photons of a light wave, and generates photocurrent based on the absorbed SPPs.

Techniques for enhancing the absorption of photons in semiconductors with the use of microstructures are described. The microstructures, such as pillars and/or holes, effectively increase the effective absorption length resulting in a greater absorption of the photons. Using microstructures for absorption enhancement for silicon photodiodes and silicon avalanche photodiodes can result in bandwidths in excess of 10 Gb/s at photons with wavelengths of 850 nm, and with quantum efficiencies of approximately 90% or more.

Techniques for enhancing the absorption of photons in semiconductors with the use of microstructures are described. The microstructures, such as pillars and/or holes, effectively increase the effective absorption length resulting in a greater absorption of the photons. Using microstructures for absorption enhancement for silicon photodiodes and silicon avalanche photodiodes can result in bandwidths in excess of 10 Gb/s at photons with wavelengths of 850 nm, and with quantum efficiencies of approximately 90% or more.

The disclosure discloses a method for forming a doped epitaxial layer of contact image sensor. Epitaxial growth is performed in times. After each time of epitaxial growth, trench isolation and ion implantation are performed to form deep and shallow trench isolation running through a large-thickness doped epitaxial layer. Through cyclic operation of epitaxial growth, trench isolation and ion implantation, the photoresist and hard mask required at each time do not need to be too thick. In the process of trench isolation and ion implantation, the photoresist and etching morphologies are good, such that the lag problem of the prepared contact image sensor is improved. By forming the large-thickness doped epitaxial layer by adopting the method for forming the doped epitaxial layer of the contact image sensor, a high-performance contact image sensor applicable to high quantum efficiency, small pixel size and near infrared/infrared can be prepared.

An imaging device is provided. The imaging device includes a semiconductor substrate; a first electrode disposed above the semiconductor substrate; a second electrode disposed above the first electrode; and a photoelectric conversion layer disposed between the first electrode and the second electrode, wherein a difference between a work function value of the first electrode and a work function value of the second electrode is 0.4 eV or more, and wherein the first electrode has a sheet resistance value of 3×10 Ω/□ to 1×10.sup.3Ω/□.