Abstract: A large area avalanche photodiode device that has a plurality of contacts formed on a bottom side that are isolated from each other by various kinds of isolation structures. In one embodiment, a cavity is formed in one layer of the avalanche photodiode that extends to a depletion region that exists in the layer as a result of a voltage applied to the device. The plurality of contacts are formed in the cavity so that each of the contacts are positioned substantially adjacent the depletion region. In another embodiment, a plurality of contacts are formed in a cavity and an isolation structure comprised of a grid of semiconductor material is formed so as to be interposed between adjacent contacts. The isolation structure preferably forms a p-n junction with the surrounding semiconductor material and the p-n junction provides isolation between adjacent contacts.

Abstract: A large area avalanche photodiode device that has a plurality of contacts formed on a bottom side that are isolated from each other by various kinds of isolation structures. In one embodiment, a cavity is formed in one layer of the avalanche photodiode that extends to a depletion region that exists in the layer as a result of a voltage applied to the device. The plurality of contacts are formed in the cavity so that each of the contacts are positioned substantially adjacent the depletion region. In another embodiment, a plurality of contacts are formed in a cavity and an isolation structure comprised of a grid of semiconductor material is formed so as to be interposed between adjacent contacts. The isolation structure preferably forms a p-n junction with the surrounding semiconductor material and the p-n junction provides isolation between adjacent contacts.

Abstract: A large area avalanche photodiode device that has a plurality of contacts formed on a bottom side that are isolated from each other by various kinds of isolation structures. In one embodiment, a cavity is formed in one layer of the avalanche photodiode that extends to a depletion region that exists in the layer as a result of a voltage applied to the device. The plurality of contacts are formed in the cavity so that each of the contacts are positioned substantially adjacent the depletion region. In another embodiment, a plurality of contacts are formed in a cavity and an isolation structure comprised of a grid of semiconductor material is formed so as to be interposed between adjacent contacts. The isolation structure preferably forms a p-n junction with the surrounding semiconductor material and the p-n junction provides isolation between adjacent contacts.

Abstract: Apparatus and method for detecting light involve applying a substantially uniform electrical potential difference between first and second spaced surfaces of a body of mercuric iodide, exposing the first surface to light and measuring an electrical current passed through the body in response to the light. The mercuric iodide may be substantially monocrystalline and the potential may be applied between a substantially transparent conductive layer at the first surface and a second conductive layer at the second surface. In a preferred embodiment, the detector is coupled to a scintillator for passage of light to the mercuric iodide in response to ionizing radiation incident on the scintillator.