Intriguing interfacial characteristics of the CS contact with MX2 (M = Mo, W; X = S, Se, Te) and MXY ((X ≠ Y) = S, Se, Te) monolayers

Abstract

Using (hybrid) first principles calculations, the electronic band structure, type of Schottky contact and Schottky barrier height established at the interface of the most stable stacking patterns of the CS–MX₂ (M = Mo, W; X = S, Se, Te) and CS–MXY ((X ≠ Y) = S, Se, Te) MS vdWH are investigated. The electronic band structures of CS–MX₂ and CS–MXY MS vdWH seem to be simple sum of CS, MX₂ and MXY monolayers. The projected electronic properties of the CS, MX₂ and MXY layers are well preserved in CS–MX₂ and CS–MXY MS vdWH. Their smaller effective mass (higher carrier mobility) render promising prospects of CS–WS₂ and CS–MoSeTe as compared to other MS vdWH in nanoelectronic and optoelectronic devices, such as a high efficiency solar cell. In addition, we found that the effective mass of holes is higher than that of electrons, suggesting that these heterostructures can be utilized for hole/electron separation. Interestingly, the MS contact led to the formation of a Schottky contact or ohmic contact, therefore we have used the Schottky Mott rule to calculate the Schottky barrier height (SBH) of CS–MX₂ (M = Mo, W; X = S, Se, Te) and CS–MXY ((X ≠ Y) = S, Se, Te) MS vdWH. It was found that CS–MX₂ (M = Mo, W; X = S, Se, Te) and CS–MXY ((X ≠ Y) = S, Se, Te) (in both model-I and -II) MS vdWH form p-type Schottky contacts. These p-type Schottky contacts can be considered a promising building block for high-performance photoresponsive optoelectronic devices, p-type electronics, CS-based contacts, and for high-performance electronic devices.