This study presents a novel Schottky infrared detector (SPBD) that overcomes the limitations of internal photoemission by introducing an optically tunable barrier. The SPBD consists of a graphene-silicon (Gr-Si) Schottky junction and a narrow bandgap lead telluride (PbTe) layer for infrared light absorption. The device's performance is enhanced by the adjustable Fermi level of graphene, which decouples the photon energy from the Schottky barrier height, allowing for broadband detection from ultraviolet to mid-wave infrared. Key features of the SPBD include a high specific detectivity of 9.83 × 10^10 cm Hz^1/2 W^−1 at 2,700 nm and an excellent specific detectivity of 7.2 × 10^9 cm Hz^1/2 W^−1 at room temperature under blackbody radiation. The SPBD demonstrates low dark current, fast response speed, and broad detection capabilities, making it a promising candidate for high-sensitivity, room-temperature infrared imaging applications.This study presents a novel Schottky infrared detector (SPBD) that overcomes the limitations of internal photoemission by introducing an optically tunable barrier. The SPBD consists of a graphene-silicon (Gr-Si) Schottky junction and a narrow bandgap lead telluride (PbTe) layer for infrared light absorption. The device's performance is enhanced by the adjustable Fermi level of graphene, which decouples the photon energy from the Schottky barrier height, allowing for broadband detection from ultraviolet to mid-wave infrared. Key features of the SPBD include a high specific detectivity of 9.83 × 10^10 cm Hz^1/2 W^−1 at 2,700 nm and an excellent specific detectivity of 7.2 × 10^9 cm Hz^1/2 W^−1 at room temperature under blackbody radiation. The SPBD demonstrates low dark current, fast response speed, and broad detection capabilities, making it a promising candidate for high-sensitivity, room-temperature infrared imaging applications.