In the scandium-hyperdoped silicon, scandiums tend to form interstitial dimers due to their lowest formation energies. The interstitial dimers of Sc formed in silicon can introduce several intermediate-bands (IBs) in the band gap, which can lead to strong sub-band gap absorption. When the two interstitial Sc atoms get close to each other, the infrared response decreases and shifts to short wavelengths. The absorption wavelength range of the interstitial dimers covers the main solar spectrum and the two primary telecommunications wavelengths, which would make material become a high efficiency IB solar cell and promising silicon-based infrared photodetector.