Direct synthesis of two-dimensional MoS₂ on p-type Si and application to solar hydrogen production

Transition metal dichalcogenides (TMDs) are promising two-dimensional (2D) materials, and MoS₂ has been specifically utilized in electronic devices and integrated circuits. However, the direct synthesis of MoS₂ on traditional semiconductors, such as silicon, remains challenging due to the hydrophobic surface of nonoxide wafers (e.g., Si, GaAs, and InP). Herein, a novel, facile, reliable, and one-step method for the direct synthesis of single-crystal MoS₂ on a p-Si wafer via hybrid thermolysis is proposed. To demonstrate the applicability of the proposed method, a MoS₂/p-Si heterojunction was fabricated and used for solar-driven hydrogen production. The as-fabricated n-MoS₂/p-Si heterojunction exhibited a benchmark current density of −13.5 ± 1 mA/cm² at 0 V and an onset potential of +0.02 V. This method reliably and efficiently produced high-quality MoS₂ crystals on a wafer scale and is sufficiently simple to overcome the challenges associated with previous approaches. The method developed herein represents a tremendous advancement in the fabrication of 2D electronic devices.