An apparatus (201) comprises a light emitter (202) and a photodetector (203) formed on a single fluid-permeable substrate (206) such that the photodetector (203) is able to detect light emitted by the light emitter (202) after interaction of the light with a user of the apparatus (201). The photodetector comprises a channel member (207) which may be made from graphene, respective source and drain electrodes (208, 209), a layer of photosensitive material (210) configured to vary the flow of electrical current through the channel member (207) on exposure to light from the light emitter (202), and a gate electrode (211). The apparatus (201) further comprises a layer of fluid-impermeable dielectric material (212) configured to inhibit a flow of electrical current between the channel member (207) and the gate electrode (211) of the photodetector (203) to enable the electrical conductance of the channel member (207) to be controlled by a voltage applied to the gate electrode (211) and to inhibit exposure of the light emitter (202) to fluid which has permeated through the fluid-permeable substrate (206). The layer of fluid-impermeable dielectric material (212) allows resilient substrates made from polymeric material to be used without the risk of damage to the overlying components caused by the permeated fluid. The dual functionality of the layer of fluid-impermeable dielectric material (212) reduces the number of fabrication steps used to form the apparatus (201) and results in a thinner, more compact device.

A method of fabricating a thin-film transistor (TFT) photodetector includes forming diffusion layers on a glass substrate or a transparent flexible substrate, wherein the diffusion layers include a P-type diffusion layer of P-type polycrystalline or amorphous silicon, for use as an active layer and P+-type diffusion layers of amorphous or polycrystalline silicon at both sides of the P-type diffusion layer, forming an insulating oxide layer on the formed diffusion layers, forming an N-type diffusion layer of polycrystalline or amorphous silicon on the insulating oxide film, forming a gate to be used as a light receiving part by photo-patterning the N-type diffusion layer, etching the generated insulating oxide layer except for only a necessary part in a photoresist (PR) patterning process, removing a remaining area of the P+-type diffusion layer except for areas to be used as a source and a drain by etching, and generating electrodes by depositing a metal in etched parts of the insulating oxide film in the source and the drain.

An optical sensor includes a graphene layer, a first electrode and a second electrode that are connected to the graphene layer, and an enhancement layer. The enhancement layer is disposed below the graphene layer to enhance the intensity of an optical electric field by surface plasmon resonance. The first electrode and the second electrode are arranged parallel to a first direction. The intensity of the optical electric field enhanced by the enhancement layer is greater on a first electrode side than on a second electrode side with respect to a centerline in the first direction of the graphene layer.

An embodiment photodetector includes a clad layer formed on a substrate, a first semiconductor layer formed on the clad layer, and a second semiconductor layer and a third semiconductor layer with the first semiconductor layer interposed therebetween formed on the clad layer. The photodetector includes a light absorbing layer made of an n-type III-V compound semiconductor formed on the first semiconductor layer through an insulating layer.

The problem of the present disclosure is to provide a photo sensor circuit that uses oxide semiconductor transistors and the operation of which is stable. The photo sensor circuit includes: a photo transistor; a first switching transistor; a second switching transistor; and a capacitance element. The photo transistor includes: a gate connected to a first wiring; a source connected to a second wiring; and a drain. The first switching transistor includes: a gate connected to a third wiring; a source connected to a fourth wiring; and a drain connected to the drain of the photo transistor. The capacitance element includes: a first terminal connected to the drain of the photo transistor; and a second terminal connected to the source of the first switching transistor. The second switching transistor includes: a gate connected to a gate line; a source connected to a signal line; and a drain connected to the first terminal of the capacitance element. Each of the photo transistor, the first switching transistor, and the second transistor includes an oxide semiconductor layer as a channel layer.

A method for forming a detection structure for detecting electromagnetic radiation includes an MOS transistor as a transducer. The method is based on the use of lateral extension elements as a doping mask for the semiconductor layer of the transistor and an etching mask for the same semiconductor layer, in order to provide contact portions of a drain and a source of the transistor.

The present invention relates to a system comprising an electronic apparatus which comprises: —an electronic device comprising: —a gate electrode structure (G, BE); —a dielectric (D) arranged over the gate electrode (G, BE); and —a charge sensing structure (CE) with a 2-dimensional charge sensing layer to provide a gate capacitance (C.sub.g) between the charge sensing structure (CE) and the gate electrode structure (G, BE) and a quantum capacitance (C.sub.q) resulting in a total capacitance (C.sub.tot); —a read-out circuit configured so that when the total capacitance (C.sub.tot) changes due to a change in the quantum capacitance (C.sub.q), an imbalance between the total capacitance (C.sub.tot) and the reference capacitance (C.sub.f) results in a change on the output voltage (V.sub.o) that is amplified to provide the read-out signal (S.sub.o). The present invention also relates to an electronic apparatus like the one of the system of the present invention.

A photosensitive field-effect transistor comprising a substrate with a source electrode, a drain electrode and a gate electrode. The transistor comprises a photoactive layer which at least partly covers the gate electrode, and a channel layer which covers the photoactive layer and at least partly covers both the source electrode and the drain electrode. The channel layer comprises a two-dimensional material whose conductivity is modulated by charge carriers transferred from the photoactive layer when electromagnetic radiation is absorbed in the photoactive layer.

A display panel includes a display pixel configured to irradiate light, an image sensor pixel included together with the display pixel in one unit pixel, including a thin film transistor (TFT) photodetector including an active layer formed of amorphous silicon or polycrystalline silicon on an amorphous transparent material, and configured to collect light reflected from a body located on the transparent material, and a processor configured to process biometrics along with positioning of the body according to the light reflected from the body.

In a graphene-semiconductor heterojunction photodetector and a method of manufacturing the same according to the present inventive concept, a source electrode and a test electrode are formed to face each other on a graphene layer, and a drain electrode is formed in a direction perpendicular to a central region portion of the graphene layer, so that the drain electrode may be physically separated from the graphene layer. Further, charges formed at the central region portion of the graphene layer are transmitted to the drain electrode through a substrate, so that high photosensitivity may be secured, and a high output voltage may be secured for the applied light. Accordingly, the drain electrode is formed at a side surface of the graphene layer, so that the size of the drain electrode may be easily controlled, and a high output voltage may be obtained.