A system and method are presented for the design and fabrication of arrays of vacuum photodiodes for application to solar power generation. In a preferred embodiment, each photodiode cell comprises a microfabricated enclosure with a hermetically sealed vacuum, an absorptive photocathode, and a transparent anode, wherein the photocathode and the anode are separated by a vacuum gap of less than about 20 micrometers. Light incident on the photocathode through the anode leads to a flux of electrons passing from the photocathode across the vacuum gap to the anode. In a further preferred embodiment, the photocathode is backed by a reflection layer with, e.g., controlled diffuse reflection, thus increasing the efficiency of energy extraction. An array of such cells may be manufactured using automated thin-film deposition and micromachining techniques.

A transmissive photocathode includes a light transmitting substrate that has a first surface on which light is incident and a second surface which emits light incident from a side of the first surface, a photoelectric conversion layer that is provided on the second surface side of the light transmitting substrate and converts the light emitted from the second surface into photoelectrons, a light transmitting conductive layer that is provided between the light transmitting substrate and the photoelectric conversion layer and is composed of a single-layered graphene, and a thermal stress alleviation layer that is provided between the photoelectric conversion layer and the light transmitting conductive layer and has light transmissivity. A thermal expansion coefficient of the thermal stress alleviation layer is smaller than a thermal expansion coefficient of the photoelectric conversion layer and larger than a thermal expansion coefficient of the graphene.

A transmissive photocathode includes a light transmitting substrate that has a first surface on which light is incident and a second surface which emits light incident from a side of the first surface, a photoelectric conversion layer that is provided on the second surface side of the light transmitting substrate and converts the light emitted from the second surface into photoelectrons, a light transmitting conductive layer that is provided between the light transmitting substrate and the photoelectric conversion layer and is composed of a single-layered graphene, and a thermal stress alleviation layer that is provided between the photoelectric conversion layer and the light transmitting conductive layer and has light transmissivity. A thermal expansion coefficient of the thermal stress alleviation layer is smaller than a thermal expansion coefficient of the photoelectric conversion layer and larger than a thermal expansion coefficient of the graphene.

A transmissive photocathode includes a light transmitting substrate that has a first surface on which light is incident and a second surface which emits light incident from a side of the first surface, a photoelectric conversion layer that is provided on the second surface side of the light transmitting substrate and converts the light emitted from the second surface into photoelectrons, a light transmitting conductive layer that is provided between the light transmitting substrate and the photoelectric conversion layer and is composed of a single-layered graphene, and a thermal stress alleviation layer that is provided between the photoelectric conversion layer and the light transmitting conductive layer and has light transmissivity. A thermal expansion coefficient of the thermal stress alleviation layer is smaller than a thermal expansion coefficient of the photoelectric conversion layer and larger than a thermal expansion coefficient of the graphene.

A transmissive photocathode includes a light transmitting substrate that has a first surface on which light is incident and a second surface which emits light incident from a side of the first surface, a photoelectric conversion layer that is provided on the second surface side of the light transmitting substrate and converts the light emitted from the second surface into photoelectrons, a light transmitting conductive layer that is provided between the light transmitting substrate and the photoelectric conversion layer and is composed of a single-layered graphene, and a thermal stress alleviation layer that is provided between the photoelectric conversion layer and the light transmitting conductive layer and has light transmissivity. A thermal expansion coefficient of the thermal stress alleviation layer is smaller than a thermal expansion coefficient of the photoelectric conversion layer and larger than a thermal expansion coefficient of the graphene.

A method of controlling the performance of a night vision device includes supplying, by a power supply, to a microchannel plate of a light intensifier tube, a control voltage that controls a gain of the microchannel plate, determining an amount of compensation to apply to the control voltage based on a change to the control voltage attributed to a change in temperature of an operating environment of the night vision device, adjusting the control voltage in accordance with the amount of compensation to obtain a compensated control voltage, and supplying, by the power supply, the compensated control voltage to the microchannel plate of the light intensifier tube. The method may further include determining whether the night vision device has been used for a predetermined amount of time, and only after that predetermined amount of time, is the method configured to supply the compensated control voltage.

A method of controlling the performance of a night vision device includes supplying, by a power supply, to a microchannel plate of a light intensifier tube, a control voltage that controls a gain of the microchannel plate, determining an amount of compensation to apply to the control voltage based on a change to the control voltage attributed to a change in temperature of an operating environment of the night vision device, adjusting the control voltage in accordance with the amount of compensation to obtain a compensated control voltage, and supplying, by the power supply, the compensated control voltage to the microchannel plate of the light intensifier tube. The method may further include determining whether the night vision device has been used for a predetermined amount of time, and only after that predetermined amount of time, is the method configured to supply the compensated control voltage.

A solar generator can include a photon-enhanced thermionic emission generator with a cathode to receive solar radiation. The photon-enhanced thermionic emission generator can include an anode that in conjunction with the cathode generates a first current and waste heat from the solar radiation. A thermoelectric generator can be thermally coupled to the anode and can convert the waste heat from the anode into a second current. A circuit can connect to the photon-enhanced thermionic emission generator and to the thermoelectric generator and can combine the first and the second currents into an output current.

A solar generator can include a photon-enhanced thermionic emission generator with a cathode to receive solar radiation. The photon-enhanced thermionic emission generator can include an anode that in conjunction with the cathode generates a first current and waste heat from the solar radiation. A thermoelectric generator can be thermally coupled to the anode and can convert the waste heat from the anode into a second current. A circuit can connect to the photon-enhanced thermionic emission generator and to the thermoelectric generator and can combine the first and the second currents into an output current.

A charge carrier multiplier structure for a light sensor, in particular an ultraviolet light sensor, is described. The charge carrier multiplier structure comprises a dielectric sheet having first and second opposite faces and having an array of holes traversing the dielectric sheet between the first and second faces, at least two photocathodes supported on the first face of the dielectric sheet that are electrically isolated from each other and which define at least two sensing regions, each photocathode having a respective work function and quantum yield and having a respective area and at least one anode supported on the second face of the dielectric sheet.