Patent attributes
A photodetector sensor array device as usable for camera chips comprises upper and lower contact layers of n+ and p+ semiconductor material either side of a light absorbing region made of either one layer, or two oppositely doped layers, of semiconductor material. Insulating trenches of dielectric material extending through the layers to form the individual pixels. Respective contacts are connected to the upper and lower contact layers so that each pixel can be reverse biased or forward biased. In operation, the device is reset with a reverse bias, and then switched to forward bias for sensing. After switching, carriers generated in response to photon absorption accumulate in potential wells in the light absorbing region and so reduce the potential barriers to the contact layers, which causes current to start to flow between the contacts after a time delay which is inversely proportional to the incident light intensity.
