Unraveling the Augmented Field Emission Performance of Molybdenum Disulfide‐Praseodymium Sulfide (MoS2@PrS) Heterostructure: A Combined Experimental and First Principles‐Based Study

Abstract The molybdenum disulfide‐praseodymium sulfide (MoS 2 ‐PrS) heterojunctions are optimally synthesized through a sophisticated three‐step procedure. Initially, MoS 2 rods are synthesized using the micellar route followed by a solid‐state reaction, forming well‐defined structures. Subsequently, PrS nanoparticles are synthesized using the same method. In the final stage, PrS nanoparticles are evenly self‐assembled onto the MoS 2 rods to create MoS 2 ‐PrS heterojunctions. This is accomplished using a combination of polyethylene glycol and ethanol as a cohesive substance, assisted by the spin coating process. The MoS 2 ‐PrS heterostructure has exceptional field emission characteristics, with a much lower turn‐on field of 2.6 V µm −1 . This is in sharp contrast to the turn‐on fields of 3.5 and 4.3 V µm −1 reported in pure MoS 2 and PrS, respectively. The emission current demonstrates remarkable stability at a predetermined value of 6 V µm −1 across 8 h, with variations limited to within ±2% of the mean value. The improved field emission (FE) capability of the MoS 2 ‐PrS heterostructure is attributed to its high enhancement factor ( β ) of 2.1 × 10 3 . The results highlight the capability of the MoS 2 ‐PrS heterostructure emitter as a promising electron source in vacuum nano/microelectronic systems. Density functional theory calculation on electronic structure is performed to support the experimental results.