Transition-metal dichalcogenides exhibit strong light–matter interactions and unique multifunctional logic behavior. Here, the strong interlayer transition and excellent broadband photodetection of GeSe/MoTe2 van der Waals (vdW) heterojunction are demonstrated. Differential charge density and photoluminescence quenching analyses reveal a strong interlayer transition between GeSe and MoTe2. In addition, density functional theory analysis predicts the formation of staggered band alignment, which contributed to the spatial segregation of photogenerated electron–hole pairs. The diode exhibited excellent optoelectronic characteristics in the visible and near-infrared region. A high responsivity of ~1.0 × 104 A/W, an excellent detectivity of ~8.4 × 1012 jones, and a fast rise and fall time of 458 and 498 μs, respectively. Finally, a two-dimensional complementary inverter consisting of p-channel GeSe and n-channel MoTe2 is examined to analyze its application for a logic inverter. The findings of this study will play a crucial role in the stimulation and fabrication of multifunctional vdW heterostructure devices.