Image sensor including nanostructure color filter

An image sensor includes a first light sensor layer including light sensing cells configured to sense first light of an incident light and generate electrical signals based on the sensed first light, and a color filter array layer disposed on the first light sensor layer, and including color filters respectively facing the light sensing cells. The image sensor further includes a second light sensor layer disposed on the color filter array layer, and configured to sense second light of the incident light and generate an electrical signal based on the sensed second light. Each of the color filters includes a nanostructure including a first material having a first refractive index, and a second material having a second refractive index greater than the first refractive index, the first material and the second material being alternately disposed with a period.