Image sensor and electronic device including the same

1. An image sensor, comprising:

a semiconductor substrate integrated with at least one first photo-sensing device configured to sense light in a blue wavelength region and at least one second photo-sensing device configured to sense light in a red wavelength region;

a color filter layer on the semiconductor substrate, the color filter layer including a blue color filter configured to selectively absorb light in a blue wavelength region and a red color filter configured to selectively absorb light in a red wavelength region; and

a third photo-sensing device on the color filter layer, the third photo-sensing device including,

a pair of electrodes facing each other,

a photoactive layer between the pair of electrodes, the photoactive layer configured to selectively absorb light in a green wavelength region; and

a semi-transmitting layer between the third photo-sensing device and the color filter layer, the semi-transmitting layer over the semiconductor substrate in a direction of light incidence, and configured to selectively transmit light in the blue wavelength region and the red wavelength region and selectively reflect light in the green wavelength region.

2. The image sensor of claim 1 , wherein

the blue wavelength region has a maximum absorption wavelength (λ max ) in a region of greater than or equal to about 400 nm and less than about 500 nm,

the red wavelength region has a maximum absorption wavelength (λ max ) in a region of greater than about 580 nm and less than or equal to about 700 nm, and

the green wavelength region has a maximum absorption wavelength (λ max ) in a region of about 500 nm to about 580 nm.

3. The image sensor of claim 1 , wherein

the pair of electrodes are light-transmitting electrodes, and

the photoactive layer includes a p-type semiconductor material and an n-type semiconductor material, at least one of the p-type semiconductor material and the n-type semiconductor material configured to selectively absorb light in the green wavelength region.

4. The image sensor of claim 1 , further comprising:

a focusing lens on the third photo-sensing device.

5. The image sensor of claim 1 , further comprising:

a metal wire beneath the at least one first photo-sensing device and the at least one second photo-sensing device.

6. The image sensor of claim 1 , wherein the semi-transmitting layer includes a plurality of first and second layers alternately stacked on the semiconductor substrate, the plurality of first layers having different refractive indices from the plurality of second layers.

7. An electronic device comprising the image sensor of claim 1 .

8. The image sensor of claim 6 , wherein the thickness of each of the plurality of first and second layers are determined by the refractive indices and reflective wavelengths of the plurality of first and second layers.

9. The image sensor of claim 6 , wherein a full width at half maximum of the green wavelength region in a light-absorption spectrum is determined by a ratio of the refractive indices of the plurality of first and second layers.

10. The image sensor of claim 6 , wherein

the plurality of first layers have the refractive index of about 1.2 to about 1.8, and

the plurality of second layers have the refractive index of about 2.1 to about 2.7.

11. The image sensor of claim 6 , wherein

each of the plurality of first layers is a silicon oxide layer, and

each of the plurality of second layers is a titanium oxide layer.

12. The image sensor of claim 6 , wherein

the semi-transmitting layer includes a plurality of silicon oxide layers and a plurality of titanium oxide layers alternately stacked on the semiconductor substrate to form 5 to 10 layers, and

each of the plurality of silicon oxide layers has a thickness of about 10 nm to 300 nm, and each of the plurality of titanium oxide layers has a thickness of about 30 nm to 200 nm.

13. The electronic device of claim 7 , wherein the image sensor further comprises:

a metal wire beneath the at least one first photo-sensing device and the at least one second photo-sensing device.

14. The electronic device of claim 7 , wherein the image sensor further comprises:

a semi-transmitting layer between the third photo-sensing device and the color filter layer, the semi-transmitting layer configured to transmit light in the blue wavelength region and the red wavelength region and configured to selectively reflect light in the green wavelength region.

15. The electronic device of claim 14 , wherein the semi-transmitting layer includes a plurality of first and second layers alternately stacked on the semiconductor substrate, the plurality of first and second layers having different refractive indices from each other.

16. The electronic device of claim 15 , wherein

the thickness of each of the plurality of first and second layers are determined by the refractive indices and reflective wavelengths of the plurality of first and second layers, and

wherein a full width at half maximum of the green wavelength region in a light-absorption spectrum is determined by a ratio of the refractive indices of the plurality of first and second layers.

17. The electronic device of claim 16 , wherein

the plurality of first layers have the refractive index of about 1.2 to about 1.8, and

the plurality of second layers have the refractive index of about 2.1 to about 2.7.

18. The electronic device of claim 17 , wherein

the semi-transmitting layer includes a plurality of silicon oxide layers and a plurality of titanium oxide layers alternately stacked on the semiconductor substrate to form 5 to 10 layers, and

each of the plurality of silicon oxide layers has a thickness of about 10 nm to 300 nm, and each of the plurality of titanium oxide layers has a thickness of about 30 nm to 200 nm.