Oxidant‐Modulated Synthesis of Polycrystalline MoS ₂ on SiO ₂ /Si with Near‐Single‐Crystal Mobility

Abstract MoS ₂ , 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 MoS ₂ films on SiO ₂ /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 MoS ₂ polycrystalline films grown on SiO ₂ /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 MoS ₂ polycrystalline films with grain sizes exceeding 50 µm on SiO ₂ /Si substrates. The transistors constructed from these films show an on/off current ratio of 10 ⁸ and peak mobilities of 72.3 cm ² 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 MoS ₂ 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.