Ultrathin molybdenum disulfide (MoS2) film obtained in atomic layer deposition: A mini-review

Atomic layer deposition (ALD) as a flexible surface-controlled fabrication technique has attracted widespread interest in numerous nanotechnology applications, which can obtain ultrathin or two-dimensional molybdenum disulfide (2D MoS2) films. The ALD technique possesses the characteristics of precise thickness control, excellent uniformity and conformality, relying on the self-limiting surface reaction. In this mini-review, the knowledge about the fabrication mechanisms and applications of ALD preparation MoS2 films are reviewed. The surface reaction pathway about ALD synthesis MoS2 is elaborated, and the corresponding factors causing saturation adsorption are discussed Two possible growth mechanisms of ALD preparation MoS2 film based on the building blocks and MoS2 islands are compared. For both, the deposition process of MoS2 can be divided into two stages, heterogeneous deposition stage and homogeneous deposition stage. The mismatch between the as-deposited MoS2 in the heterodeposition and the lattice structure of the substrate surface is a key factor leading to the poor crystallinity of as-deposited MoS2. In addition, the extensions of ALD MoS2 technique to improve the as-deposited film quality are discussed. Finally, the applications of ALD deposited MoS2 film are summarized, and future perspectives are outlined.