Low Carbon Residue Growth of Wafer-Scale MoS₂

Residues introduced are often underestimated and face challenges in purification during the material synthesis. For wafer-scale 2D transition metal dichalcogenides preparation, the organic-mediated growth route is favorable and optimal due to its precise controllability of source mass. However, the carbon residue generated from organic precursors severely damages the intrinsic electrical properties of the material. Especially for vapor organic source deposition approaches, the formation of amorphous carbon is almost inevitable due to the continuous introduction of gaseous organic sources. Here, a PAA-assisted strategy is developed to prepare carbon-free film by utilizing solid metalorganic sources and non-organic sulfur. The solid precursor blocks the supply of carbon and the sulfur further converts the remaining C into CS₂ to achieve effective elimination with a concentration below 1%. Carboxy-rich linear polyacrylic acid (PAA) is strategically selected as the organic skeleton and obtain a 4-inch carbon-free uniform MoS₂ wafer. The field-effect transistor arrays are fabricated and the devices exhibit a high carrier mobility of 13.3 cm²V^-1s^-1 with an ultra-low leakage current density. The PAA-assisted method provides a high-purity organic-mediated approach to efficiently synthesize high-quality MoS₂ wafers.