Epitaxially integrated protection diodes for monochromatic photosensitive diodes

DWPI Title: Monochromatic photosensitive device has third layer of narrower bandgap material having second doping type different from first doping type, where third layer is adjacent to second layer, and protection diode, has fourth layer of wider bandgap material having first doping type
Abstract: Monochromatic photosensitive devices (MPDs) having series connected photosensitive diode cell arrays in two configurations are disclosed. The MPDs employ a protection diode to bypass either one or multiple photosensitive diodes in each photosensitive diode cell should a photosensitive diode fail as an open circuit or become blocked from the monochromatic light. The protection diode is vertically (epitaxial growth direction) integrated with a photosensitive diode layer structure during epitaxial growth, thereby permitting monolithic fabrication of the one or multiple photosensitive diode cells. The bulk of the one or multiple photosensitive diodes are formed of a material having a bandgap corresponding to the wavelength of the monochromatic light, while the protection diodes are formed of a material having a bandgap greater than the wavelength of the monochromatic light. The monochromatic light passes through the protection diode before being absorbed by the one or multiple photosensitive diodes.
Use: Monochromatic photosensitive device.
Advantage: The photosensitive diode has a reflective surface formed on the first layer on a first surface opposite the second layer, the reflective surface covering substantially all of the first surface, the reflective surface reflecting the substantially monochromatic light; the first surface of the first layer of each photosensitive diode has a diffraction pattern formed, the diffraction pattern diffracting the substantially monochromatic light; and an absorption volume of each protection diode generating a high energy protection current in a high energy photon environment, an absorption volume of each photosensitive diodes generating a high energy photocurrent in the high energy photon environment, and the high energy protection current is about equal to the high energy photocurrent. The MPD cell array may be operating in an environment with high energy photon radiation, the high energy photons separate and apart from the substantially monochromatic light. These high energy photons may, for example, have an energy greater than about 100 eV, in such environments, the protection diodes may serve an additional purpose. Specifically, the protection diodes may inhibit or reduce current spikes, due to pulses of high energy photon radiation, from affecting operation of components powered by the MPD cell array, when operating in these high energy photon radiation environments, it is preferable that the current created in the protection diode, i.e., the high energy protection current, be equal to the current created in the corresponding photosensitive diode(s), i.e., the high energy photocurrent, so that the two currents may cancel each other. This may be done, for example, by designing the MPD cell array such that the absorption volume for the protection diode is the same as the absorption volume for the corresponding photosensitive diode(s), the thicknesses of the various layers may be adjusted and/or the areas of the protection diode and the corresponding photosensitive diode(s) may be adjusted.
Novelty: Monochromatic photosensitive device ( MPD) comprises photosensitive diode cells that are electrically connected in series, where each of photosensitive diode cells has a photosensitive diode. The photosensitive diode is formed of a narrower bandgap material and a wider bandgap material, a bandgap of the narrower bandgap material corresponding substantially to an energy of a photon of a substantially monochromatic light, a bandgap of the wider bandgap material being greater than the energy of a photon of the substantially monochromatic light. The photosensitive diode has a first layer of wider bandgap material having a first doping type, a second layer of nominally intrinsic narrower bandgap material, the second layer adjacent the first layer. A third layer of narrower bandgap material having a second doping type different from the first doping type, the third layer adjacent the second layer. A protection diode, has a fourth layer of wider bandgap material having the first doping type.
Filed: 3/2/2022
Application Number: US17684955A
Tech ID: SD 15129.1
This invention was made with Government support under Contract No. DE-NA0003525 awarded by the United States Department of Energy/National Nuclear Security Administration. The Government has certain rights in the invention.
Data from Derwent World Patents Index, provided by Clarivate
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