Growth of multiple WS₂/SnS layered semiconductor heterojunctions

Abstract

Both WS2 and SnS are 2-dimensional, van der Waals semiconductors, but with different crystal structures. Heteroepitaxy of these materials was investigated by growing 3 alternating layers of each of these materials using atomic layer deposition on 5 cm × 5 cm substrates. Initially, WS2 and SnS films were grown and characterized separately. Back-gated transistors of WS2 displayed n-type behavior with an effective mobility of 12 cm(2) V(-1) s(-1), whereas SnS transistors showed a p-type conductivity with a hole mobility of 818 cm(2) V(-1) s(-1). All mobility measurements were performed at room temperature. As expected, the heterostructure displayed an ambipolar behavior with a slightly higher electron mobility than that of WS2 transistors, but with a significantly reduced hole mobility. The reason for this drop can be explained with transmission electron micrographs that show the striation direction of the SnS layers is perpendicular to that of the WS2 with a 15 degree twist, hence the holes have to pass through van der Waals layers that results in drop of their mobility.

Atomic Layer Growth of InSe and Sb2Se3 Layered Semiconductors and Their Heterostructure

“…Then, the growth will proceed layer by layer, which is ideal for growth of a 2D film. We have found that organometallic or chloride-based metal precursors (with sufficient vapor pressure) work well on SiO 2 covered substrates, as we have previously demonstrated with other metal chalcogenides [5,43,44].…”

“…The ability to tune the direct band gap of many of these materials, by controlling their thickness, allows further flexibility for the design and fabrication of optoelectronic devices. However, to date, most attention has been focused on 2D transition metal dichalcogenides of structure C-M-C (C = chalcogen, M = metal), where one metal atom is sandwiched between two chalcogen atoms [4][5][6][7]. There are other forms of metal chalcogenides that are equally intriguing.…”

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

“…Especially, the dangling bonds on the interface of the heterostructures by mechanical transfer procedure may adsorb other molecules such as oxygen or water, resulting in passivation which is harmful for advanced electronic devices. Therefore, there are many attempts on the epitaxial growth of heterostructures 245, 246. Jin and co‐workers245 have achieved heteroepitaxial growth of thin layers of MoS 2 , WS 2 , and WSe 2 on SnS 2 microplates via a CVD procedure employing metal chlorides and sulfide or selenium powders at low temperature (<500 °C).…”

“…They presented high performance 2D–2D tunneling FETs such as the subthreshold swing of 100 meV and the maximum switching ratio I on / I off of 10 7 . What is more, Rouvimov and co‐workers246 have reported the growth of multiple WS 2 /SnS layered heterostructures by atomic layer deposition, and the heterojunction based FET exhibited an ambipolar behavior with the electron mobility higher than that of WS 2 based FETs.…”

Specific Features of Content Dependences for Energy Gap in InxTl1-xI Solid State Crystalline Alloys

“…For example, there is observed an enhanced attention to the study of physical properties of the crystalline semiconductor compounds A III B VII , including binary layered crystals [3,4]. The traditional crystals with heavy cations, like TlI and TlIn-I [5,6], may serve as the suitable modeling crystals and as those for the search and design of novel crystals.…”