Abstract: An apparatus including an array of field-effect transistors, each field-effect transistor including a channel, source and drain electrodes, and a gate electrode configured to enable the flow of electrical current to be varied, the gate electrode separated from the channel by a dielectric material configured to inhibit a flow of electrical current between the channel and gate electrode, wherein the gate electrode of each field-effect transistor is connected in parallel to the gate electrodes of the other field-effect transistors in the array, and wherein a respective two-terminal current-limiting component is coupled to each gate electrode such that, in the event that a defect in the dielectric material of a particular field-effect transistor allows a leakage current to flow between the channel and gate electrode of that field-effect transistor, the respective two-terminal current-limiting component limits the magnitude of the leakage current.

Abstract: A photosensitive field-effect transistor which can be configured to provide an electrical response when illuminated by electromagnetic radiation incident on the transistor. The field-effect transistor has a channel (13) made from a two-dimensional material and comprises a photoactive layer (22) which can be configured to donate charge carriers to the transistor channel (13) when electromagnetic radiation is absorbed in the photoactive layer (22). The photosensitive field-effect transistor comprises a top electrode (21) which is in contact with the photoactive layer on one or more contact areas which together form a contact pattern. With a suitably patterned top electrode (21), a voltage applied to the electrode can function as an electrical shutter which can switch the photosensitive field-effect transistor between a light-sensitive state and a light-immune state.

Abstract: 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.

Abstract: An apparatus including an array of field-effect transistors, each field-effect transistor including a channel, source and drain electrodes, and a gate electrode configured to enable the flow of electrical current to be varied, the gate electrode separated from the channel by a dielectric material configured to inhibit a flow of electrical current between the channel and gate electrode, wherein the gate electrode of each field-effect transistor is connected in parallel to the gate electrodes of the other field-effect transistors in the array, and wherein a respective two-terminal current-limiting component is coupled to each gate electrode such that, in the event that a defect in the dielectric material of a particular field-effect transistor allows a leakage current to flow between the channel and gate electrode of that field-effect transistor, the respective two-terminal current-limiting component limits the magnitude of the leakage current.

Abstract: A photosensitive field-effect transistor which can be configured to provide an electrical response when illuminated by electromagnetic radiation incident on the transistor. The field-effect transistor has a channel (13) made from a two-dimensional material and comprises a photoactive layer (22) which can be configured to donate charge carriers to the transistor channel (13) when electromagnetic radiation is absorbed in the photoactive layer (22). The photosensitive field-effect transistor comprises a top electrode (21) which is in contact with the photoactive layer on one or more contact areas which together form a contact pattern. With a suitably patterned top electrode (21), a voltage applied to the electrode can function as an electrical shutter which can switch the photosensitive field-effect transistor between a light-sensitive state and a light-immune state.

Abstract: An apparatus, method and computer program for operating an apparatus. The apparatus comprises: a scintillator and an array of photodetectors; the scintillator configured to be rotatable around the periphery of a computed tomography scanner, the scintillator configured to receive X-rays incident on the scintillator, convert the received X-rays to visible light and transmit the visible light towards a corresponding photodetector of the array of photodetectors; and the array of photodetectors fixed around the periphery of the computed tomography scanner, each of the photodetectors in the array of photodetectors configured to output an electrical signal in response to detecting the visible light received from the scintillator.

Abstract: 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.

Abstract: There are disclosed various apparatuses and methods for tuning a resonance frequency. In some embodiments there is provided an apparatus (200) comprising at least one input electrode (202, 204) for receiving radio frequency signals; a graphene foil (210) for converting at least part of the radio frequency signals into mechanical energy; at least one dielectric support element (212) to support the graphene foil (210) and to space apart the at least one input electrode (202, 204) and the graphene foil (210). The graphene foil (210) has piezoelectric properties. In some embodiments there is provided a method comprising receiving radio frequency signals by at least one input electrode (202, 204) of an apparatus (200); providing a bias voltage to the apparatus (200) for tuning the resonance frequency of the apparatus (200); and converting at least part of the radio frequency signals into mechanical energy by a graphene foil (210) having piezoelectric properties.

Abstract: An apparatus, including a quantum dot graphene field effect transistor configured to operate such that photons incident thereon cause electron-hole pairs to be formed; a connector element connected to the back gate of the transistor; a switch element as an output switch to provide an output for a current flowing through the transistor. The transistor is configured to be back gate biased via the connector element connected to the back gate such that the electrons or the holes formed are trapped in an at least one quantum dot and respectively the holes or the electrons migrate to the channel of the transistor. A drain to source voltage connected to the transistor causes a current proportional to the charge of the holes or electrons trapped at the quantum dots by the electrons or holes to flow in the channel.

Abstract: An apparatus comprising at least one pair of a first inner and second outer photodetector, each photodetector comprising a channel member, respective source and drain electrodes configured to enable a flow of electrical current through the channel member between the source and drain electrodes, and a plurality of quantum dots configured to generate electron-hole pairs on exposure to incident electromagnetic radiation to produce a detectable change in the electrical current flowing through the channel member. The first inner and second outer photodetectors are configured to generate electron-hole pairs which produce an increase and decrease in electrical current through the channel members. The first inner and the second outer photodetectors share a common channel member, which is partitioned by one or more of the respective source and drain electrodes respectively extending in two dimensions such that the first inner photodetector is defined within the second outer photodetector.

Abstract: An apparatus comprising a piezoelectric diaphragm positioned between opposing first and second electrodes, the piezoelectric diaphragm comprising a stack of graphene oxide layers between respective electrode-engaging layers of reduced graphene oxide, wherein the apparatus is configured to have one or more of a sound output mode and a sound input mode such that: in the sound output mode, the first and second electrodes are configured to apply a voltage to the reduced graphene oxide layers to generate an electric field across the graphene oxide stack, the generated electric field causing vibration of the piezoelectric diaphragm to produce a sound output wave corresponding to the applied voltage, and in the sound input mode, the reduced graphene oxide layers are configured to collect electrical charge which is induced in the graphene oxide layers by vibration of the piezoelectric diaphragm in response to a sound input wave, the collected electrical charge creating a voltage between the first and second electrode

Abstract: Apparatus, electronic device, system and method comprising a first element (102) configured to receive a first signal and convert the first signal to a second signal, a second element (104) configured to relay the second signal to a third element (106, 108), the third element (106, 108) being configured to convert the second signal to a third signal and to send the third signal; wherein the first element (102) is configured to convert the first signal to the second signal in such a way that the conversion is dependent on the physio-chemical structure of at least part of the first element (102). In some embodiments the first element comprises a photoacoustic sensor comprising at least one graphene layer, the second element comprises a mechanical wave transmission line, and the third element comprises carbon nanotube antennas.

Abstract: An apparatus comprising a piezoelectric diaphragm positioned between opposing first and second electrodes, the piezoelectric diaphragm comprising a stack of graphene oxide layers between respective electrode-engaging layers of reduced graphene oxide, wherein the apparatus is configured to have one or more of a sound output mode and a sound input mode such that: in the sound output mode, the first and second electrodes are configured to apply a voltage to the reduced graphene oxide layers to generate an electric field across the graphene oxide stack, the generated electric field causing vibration of the piezoelectric diaphragm to produce a sound output wave corresponding to the applied voltage, and in the sound input mode, the reduced graphene oxide layers are configured to collect electrical charge which is induced in the graphene oxide layers by vibration of the piezoelectric diaphragm in response to a sound input wave, the collected electrical charge creating a voltage between the first and second electrode

Abstract: An apparatus comprising at least one pair of a first inner and second outer photodetector, each photodetector comprising a channel member, respective source and drain electrodes configured to enable a flow of electrical current through the channel member between the source and drain electrodes, and a plurality of quantum dots configured to generate electron-hole pairs on exposure to incident electromagnetic radiation to produce a detectable change in the electrical current flowing through the channel member. The first inner and second outer photodetectors are configured to generate electron-hole pairs which produce an increase and decrease in electrical current through the channel members. The first inner and the second outer photodetectors share a common channel member, which is partitioned by one or more of the respective source and drain electrodes respectively extending in two dimensions such that the first inner photodetector is defined within the second outer photodetector.

Abstract: An apparatus, method and computer program for operating an apparatus. The apparatus comprises: a scintillator and an array of photodetectors; the scintillator configured to be rotatable around the periphery of a computed tomography scanner, the scintillator configured to receive X-rays incident on the scintillator, convert the received X-rays to visible light and transmit the visible light towards a corresponding photodetector of the array of photodetectors; and the array of photodetectors fixed around the periphery of the computed tomography scanner, each of the photodetectors in the array of photodetectors configured to output an electrical signal in response to detecting the visible light received from the scintillator.

Abstract: An apparatus including an oxidation cell configured to oxidize carbon monoxide to produce carbon dioxide; and a sensor configured to detect carbon dioxide produced by the oxidation cell.

Abstract: A system including a wireless device configured to apply selective error correction coding to data content to produce first data and second data, wherein the first and the second data being error correction coded differently; maintain the first data and the second data in a non-volatile memory of the wireless device; receive an electromagnetic signal for powering the wireless device; and transmit the first data and the second data over a short-range wireless link. The system further includes an apparatus configured to transmit an electromagnetic signal for powering the wireless device; receive first and second data over a short-range wireless link, wherein the first data and the second data being error correction coded differently; and apply selective error correction decoding to the first data and the second data to produce data content.

Abstract: An apparatus, including a quantum dot graphene field effect transistor configured to operate such that photons incident thereon cause electron-hole pairs to be formed; a connector element connected to the back gate of the transistor; a switch element as an output switch to provide an output for a current flowing through the transistor. The transistor is configured to be back gate biased via the connector element connected to the back gate such that the electrons or the holes formed are trapped in an at least one quantum dot and respectively the holes or the electrons migrate to the channel of the transistor. A drain to source voltage connected to the transistor causes a current proportional to the charge of the holes or electrons trapped at the quantum dots by the electrons or holes to flow in the channel.

Abstract: An apparatus with at least two electromagnetic radiation sensor cells that include graphene as an electromagnetic radiation absorbing material and electrical connections between the at least two sensor cells. The electrical connections are at least partially made of graphene.

Abstract: Apparatus, electronic device, system and method comprising a first element (102) configured to receive a first signal and convert the first signal to a second signal, a second element (104) configured to relay the second signal to a third element (106, 108), the third element (106, 108) being configured to convert the second signal to a third signal and to send the third signal; wherein the first element (102) is configured to convert the first signal to the second signal in such a way that the conversion is dependent on the physio-chemical structure of at least part of the first element (102). In some embodiments the first element comprises a photoacoustic sensor comprising at least one graphene layer, the second element comprises a mechanical wave transmission line, and the third element comprises carbon nanotube antennas.