A binary image sensor includes a plurality of unit pixels on a substrate having a surface on which light is incident. At least one quantum dot is disposed on the surface of a substrate. A column sense amplifier circuit is configured to detect binary information of a selected unit pixel among the plurality of unit pixels from a voltage or a current detected from the selected unit pixel, and a processing unit is configured to process binary information of the respective unit pixels to generate pixel image information. Related devices and methods of operation are also discussed.