SOLID-STATE IMAGING ELEMENT AND IMAGING SYSTEM

A solid-state image sensor includes a first semiconductor, and a second semiconductor having a composition different from that of the first composition and electrically connected to the first semiconductor. The first semiconductor includes a photodiode configured to convert light incident on the photodiode into charge carriers; a plurality of first carrier storages for storing the charge carriers; and a transfer gate configured to transfer the charge carriers to a selected one of the first carrier storages. The second semiconductor includes a plurality of second carrier storages and a potential detection node. The second carrier storages are each configured to store charge carriers based on the charge carriers stored in a corresponding one of the first carrier storages. The potential detection node is configured to detect the electric potential of each of the second carrier storages. The solid-state image sensor further includes a reset transistor configured to reset the electric potential of each of the first carrier storages to a predetermined electric potential.