Hyperdoping is the incorporation of impurities into semiconductors with concentrations exceeding the equilibrium solubility by orders of magnitude (up to ~10²⁰ cm⁻³). It opens the way to the formation of impurity bands in the silicon band gap. The chalcogens' (S, Se, Te) incorporation allows to achieve enhanced absorption coefficient (10²—10⁴ cm⁻¹) in the infrared range (1—6 μm) due to subband transitions. The review covers the mechanisms of formation of impurity states, synthesis methods (ion implantation, laser processing), as well as structural, electrical, and optical properties. A special focus is on the application in infrared photodetectors operating at room temperature and solving instability problems (segregation, defects) through annealing optimization, selective doping, and heterostructures.