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consequently low carrier density limit its performance in electronic devices. [10] The carrier mobility of monolayer MoS 2 is relatively low and can even be seriously vulnerable against the optical phonons, defect and impurities. [11][12][13] Multilayer MoS 2 exposes much higher current density (400-1500 µA µm −1 ) and mobility (200-500 cm 2 V −1 s −1 ) than monolayer MoS 2 (current density: 50-700 µA µm −1 ; mobility: 70-100 cm 2 V −1 s −1 ), [14][15][16][17] making them more suitable for electronic application such as field effect transistors (FETs) and 2D device integrated circuits. Quantum transport simulations suggested that the bilayer and trilayer MoS 2 -based FETs could show better performance than the monolayer MoS 2 . [18][19][20] Excitingly, the bilayer MoS 2 based devices have been successfully demonstrated with very promising performance in experimental works. [21,22] Liu et al. produced bilayer MoS 2 films by the Scotch-tape technique and fabricated FETs devices with high on/ off ratio of 1 × 10 8 and field effect mobility of 517 cm 2 V −1 s −1 . [23] In addition, it was shown that the layerdependent electronic structures of multilayer MoS 2 can give rise to the unique optoelectronic response in devices. [24] However, the growth of large-area uniform multilayer MoS 2 , as the prerequisite of industrial application, is still very challenging. [25] Actually, the grand breakthrough was not made until very recently in the wafer-scale growth of monolayer MoS 2 single crystal films, in comparison with which the growth of large-area uniform multilayer MoS 2 is severely lagged. [26] Presently, the growth of multilayer MoS 2 films has commonly been achieved through the layer-by-layer growth mode via chemical vapor deposition (CVD) methods. [16,27,28] However, the multilayer MoS 2 films prepared by this route show poor uniformity on the thickness and domain size. This is attributed to that the nucleation of top-layer has to be occurred on the surface of previously grown bottom MoS 2 films, making it difficult to control the thickness and domain size of grown MoS 2 domain. Besides, the layer-by-layer growth mode would suffer from the synthesis time penalty and insufficient growth time will lead to a much smaller area of the upper MoS 2 layer than that of the lower layer and consequently a much smaller usable area of the grown film. [13] Hong et al. claimed that the growth of wafer-scale MoS 2 polycrystalline films within five layers could Multilayer MoS 2 shows superior performance over the monolayer MoS 2 for electronic devices while the growth of multilayer MoS 2 with controllable and uniform thickness is still very challenging. It is revealed by calculations that monolayer MoS 2 domains are thermodynamically much more favorable than multilayer ones on epitaxial substrates due to the competition between surface interactions and edge formation, leading accordingly to a layer-bylayer growth pattern and non-continuously distributed multilayer domains with uncontrollable thickness uniformity. The thermodynamics ...

The temperature distribution, number of Al–O bonds and hydrogen yield evolution with time.

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