p-Type Al-Doped MoS2 Nanosheet Films: Electronic and Chemical Interface Properties with Gold for Electronic Device Integration

High-performance optoelectronic devices based on two-dimensional transition-metal dichalcogenides require precise control of the intrinsic and interfacial properties with metallic contacts. We studied aluminum doping and its effect on the chemical and electronic properties of MoS₂ nanosheet films prepared by plasma-enhanced atomic layer deposition (ALD). We combined photoelectron (XPS/UPS) and UV–vis absorption spectroscopies, revealing that Al introduction decreases the Fermi level-to-valence band energy difference of MoS₂ from 0.61 to 0.04 eV and suppresses Au sputtering damage. Stepwise Au sputtering on MoS₂ films reveals chemical modifications in the undoped nanosheets, whereas Al doping stabilizes the material, preventing such an alteration. These findings highlight the potential of Al doping not only for precise control of electronic properties but also for improving the chemical stability of MoS₂ nanosheets, making them more suitable for advanced optoelectronic applications.