Tuning the orientation of few-layer MoS2 films using one-zone sulfurization

SOJKOVÁ, Michaela – VÉGSÖ, Karol – MRKYVKOVA, Naďa – HAGARA, Jakub – HUTÁR, Peter – ROSOVÁ, Alica – ČAPLOVIČOVÁ, Mária – LUDACKÁ, Uršula – SKÁKALOVÁ, Viera – MAJKOVÁ, Eva – ŠIFFALOVIČ, Peter

In RSC Advances. Vol. 9, iss. 51 (2019)



Few-layer MoS2 films are promising candidates for applications in numerous areas, such as photovoltaics, photocatalysis, nanotribology, lithium batteries, hydro-desulfurization catalysis and dry lubricants, especially due to their distinctive electronic, optical, and catalytic properties. In general, two alignments of MoS2 layers are possible – the horizontal and the vertical one, having different physicochemical properties. Layers of both orientations are conventionally fabricated by a sulfurization of pre-deposited Mo films. So far, the Mo thickness was considered as a critical parameter influencing the final orientation of MoS2 layers with horizontally and vertically aligned MoS2 grown from thin (1 nm) and thick (3 nm) Mo films, respectively. Here, we present a fabrication protocol enabling the growth of horizontally or vertically aligned few-layer MoS2 films utilizing the same Mo thickness of 3 nm. We show that the sulfur vapor is another parameter influencing the growth mechanism, where a sulfurization with higher sulfur vapor pressure leads to vertical MoS2 layers and slow sulfur evaporation results in horizontally aligned layers for a thicker Mo starting layer.