A silicon light-receiving device is provided. In the device, a substrate is based on n-type or p-type silicon. A doped region is ultra-shallowly doped with the opposite type dopant to the dopant type of the substrate on one side of the substrate so that a photoelectric conversion effect for light in a wavelength range of 100-1100 nm is generated by a quantum confinement effect in the p-n junction with the substrate. First and second electrodes are formed on the substrate so as to be electrically connected to the doped region. Due to the ultra-shallow doped region on the silicon substrate, a quantum confinement effect is generated in the p-n junction. Even though silicon is used as a semiconductor material, the quantum efficiency of the silicon light-receiving device is far higher than that of a conventional solar cell, owing to the quantum confinement effect. The silicon light-receiving device can also be formed to absorb light in a particular or large wavelength band, and used as a solar cell.