LAUSR

As an eye‐catching 2D material, MoS2 has tunable optical and electrical properties. However, the rapid recombination of electron‐hole pairs intrinsically significantly hinders the performance improvement of MoS2 photodetectors. Achieving carrier manipulation to suppress recombination is crucial and challenging for MoS2 photodetectors. Herein, we report three MoS2 photodetectors decorated with platinum single atoms (Pt SAs), platinum single‐layer clusters (Pt SCs), and platinum nanoclusters (Pt NCs) via an impregnation method. Carrier recombination in MoS2 is suppressed by growing Pt SAs, Pt SCs, and Pt NCs. Furthermore, Pt SAs, Pt SCs, and Pt NCs have different effects on carrier behavior due to the size effect and disparate interactions with MoS2. Among the Pt SA/MoS2, Pt SC/MoS2, and Pt NC/MoS2 devices, Pt SC/MoS2 exhibits a responsivity (R) of 1.44 × 102 A W−1 and a specific detectivity (D*) of 1.07 × 1010 Jones under 532 nm illumination with a power density of 0.5 mW cm−2. This work will deepen the understanding of the relationship between the size effect and carrier behavior and provide a theoretical basis for carrier manipulation of photodetectors.