Image sensors and electronic devices

An image sensor, comprising:

• a first photo-sensing device on a semiconductor substrate, the first photo-sensing device being configured to sense light in a first wavelength spectrum associated with a first color,
• a second photo-sensing device integrated in the semiconductor substrate, the second photo-sensing device being configured to sense light of in a second wavelength spectrum associated with a second color, and
• a third photo-sensing device integrated in the semiconductor substrate, the third photo-sensing device being configured to sense light in a third wavelength spectrum associated with a third color,
• wherein the first photo-sensing device and the second photo-sensing device are overlapped with each other in a thickness direction of the semiconductor substrate, the thickness direction being perpendicular to an upper surface of the semiconductor substrate,
• wherein the first photo-sensing device and the third photo-sensing device are overlapped with each other in the thickness direction,
• wherein the second photo-sensing device and the third photo-sensing device are not overlapped with each other in the thickness direction,
• wherein the second photo-sensing device and the third photo-sensing device each include
• an upper surface that is proximate to the upper surface of the semiconductor substrate,
• a lower surface facing the upper surface and distal from the upper surface of the semiconductor substrate, and
• a doped region between the upper surface and the lower surface,
• wherein the upper surface of the third photo-sensing device is distal from the upper surface of the semiconductor substrate in relation to the upper surface of the second photo-sensing device, and
• wherein the doped region of the third photo-sensing device is thicker, in the thickness direction, than the doped region of the second photo-sensing device.