The image sensor structure includes a substrate, a readout circuit array, a photoelectric layer and a filter layer. The filter layer has a first spectrum defining a first wavelength. The photoelectric layer has a second spectrum defining a second wavelength. The second wavelength is longer than the first wavelength. The first wavelength corresponds to a first line passing through a first point and a second point on a curve of the first spectrum of the filter layer. The first point aligns with an extinction coefficient of 0.9. The second point aligns with an extinction coefficient of 0.1. The second wavelength corresponds to a second line passing through a third point and a fourth point on a curve of the second spectrum of the photoelectric layer. The third point aligns with an extinction coefficient of 0.9. The fourth point aligns with an extinction coefficient of 0.1.