Oxidant-Modulated Synthesis of Polycrystalline MoS₂ on SiO₂/Si with Near-Single-Crystal Mobility

MoS₂, a 2D semiconductor, has emerged as an ideal channel material for transistors in the post-Moore era due to its atomic thickness, high mobility, and excellent gate control capability. The direct growth of 2D MoS₂ films on SiO₂/Si is crucial for ensuring compatibility with complementary metal-oxide-semiconductor (CMOS) processes while avoiding the damage and defects often associated with transfer processes. However, 2D MoS₂ polycrystalline films grown on SiO₂/Si suffer from small grain sizes, high grain boundary densities, and poor electrical performance. In this study, an oxygen-modulated method is employed to enable the synthesis of inch-scale, high-quality 2D MoS₂ polycrystalline films with grain sizes exceeding 50 µm on SiO₂/Si substrates. The transistors constructed from these films show an on/off current ratio of 10⁸ and peak mobilities of 72.3 cm² V^-1 s^-1. Notably, the mobility demonstrates an order of magnitude improvement compared to films that lack oxidant modulation, comparable to the performance of several reported single-crystal MoS₂ films grown on sapphire substrates. This research offers a direct and effective strategy for growing large-area, high-quality 2D semiconductor films on amorphous oxide substrates, establishing a solid foundation for enhancing the performance of related electronic devices.