High voltage generation using reconfigurable photodiodes in pixel array

An imaging sensor includes a pixel array containing photodiodes, the photodiodes being isolated from one another by full thickness deep trench isolations. Row control circuitry controls which rows of the pixel array operate in an imaging mode and which rows of the pixel array operate in an energy harvesting mode, on a row-by-row basis. Switch circuitry selectively connects different groups of photodiodes in rows operating in the energy harvesting mode into forward biased series configurations between a voltage output line and a ground line, or into forward biased parallel configurations between the voltage output line and the ground line. In the forward biased series configurations, the cathode of at least one photodiode of a given group of photodiodes is directly electrically connected to ground.