An optical sensor device includes a semiconductor substrate including a conversion region to convert an electromagnetic signal into photo-generated charge carriers, a read-out node configured to read-out a first portion of the photo-generated charge carriers, a control electrode, which is formed in a trench extending into the semiconductor substrate, and a doping region in the semiconductor substrate, where the doping region is adjacent to the trench, where the doping region has a doping type different from the read out node, and where the doping region has a doping concentration so that the doping region remains depleted during operation.