Controlled Synthesis of Highly Crystalline MoS₂ Flakes by Chemical Vapor Deposition

Abstract

The controlled synthesis of highly crystalline MoS2 atomic layers remains a challenge for the practical applications of this emerging material. Here, we developed an approach for synthesizing MoS2 flakes in rhomboid shape with controlled number of layers by the layer-by-layer sulfurization of MoO2 microcrystals. The obtained MoS2 flakes showed high crystallinity with crystal domain size of ~10 μm, significantly larger than the grain size of MoS2 grown by other methods. As a result of the high crystallinity, the performance of back-gated field effect transistors (FETs) made on these MoS2 flakes was comparable to that of FETs based on mechanically exfoliated flakes. This simple approach opens up a new avenue for controlled synthesis of MoS2 atomic layers and will make this highly crystalline material easily accessible for fundamental aspects and various applications.

Chemical Vapor Deposition of High‐Quality Large‐Sized MoS2 Crystals on Silicon Dioxide Substrates

“…The Mo 3 d 3/2 and 3 d 5/2 peaks are located at ≈230.0 and ≈233.2 eV, respectively, while the S 2 p 1/2 and S 2 p 3/2 peaks are located at ≈164.0 and ≈162.9 eV, respectively. These peak positions are consistent with the reported values for 2H‐MoS 2 crystals 34. The positions of the Mo peaks indicate the reduction of Mo from Mo 6+ (MoO 3 ) to Mo 4+ (MoS 2 ).…”

“…Among these methods, chemical vapor deposition (CVD) is most promising in terms of scalability, simple operation and low cost, and has been used to grow various 2D materials directly on dielectric substrates 17, 18, 19, 20, 21, 22, 23, 24, 25, 26. However, similar to other TMDs,19, 20, 21 CVD‐grown continuous MoS 2 film suffer from a high density of rotational domain boundaries 27, 28.…”

Booming Development of Group IV–VI Semiconductors: Fresh Blood of 2D Family

“…CVD‐grown graphene has made great breakthrough in the growth of large‐area graphene 17, 155, 156, 157, 158, 159, 160. Recently, the synthesis of 2DLMs via CVD methods has been illustrated in many reports especially for MoS 2 ,30, 31, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185 which also shows promising applications in electronics and optoelectronics. Up to now, there are several reports on synthesizing 2D GIVMCs nanoflakes via CVD method, which is still at the initial stage.…”

Two-dimensional inorganic analogues of graphene: transition metal dichalcogenides

“…The substrates were placed in a cold zone at 650 • C [46]. Feng et al [52] have also reported the synthesis of uniformly distributed monolayer MoS 2(1−x) Se 2x alloys on SiO 2 /Si substrates through the direct evaporation of MoSe 2 [44], (d,e) adapted with permission from Li et al [45], (f ,g) adapted with permission from Wu et al [46] and (h) adapted with permission from Liu et al [47].…”