A novel light-sensing scheme based on a silicon/fullerene-derivative heterojunction allows optoelectronic detection in the near- to mid-infrared (IR), which is fully compatible with complementary metal oxide semiconductor (CMOS) technology. Although silicon and the fullerene derivative do not absorb in the IR, a heterojunction of these materials absorbs and generates a photocurrent (PC) in the near-to mid-IR, presumably caused by an interfacial absorption mechanism.