Field-Effect Transistor Based on MoSi2N4 and WSi2N4 Monolayers Under Biaxial Strain: A Computational Study of the Electronic Properties

The electronic properties of a field-effect transistor with two different structures of MoSi₂N₄ and WSi₂N₄ monolayers as the channel material in the presence of biaxial strain are investigated. The band structures show that these compounds are semiconductors with an indirect bandgap. Their band gaps can be adjusted by applying in- plane biaxial strain. In the following, the variation of the energies of the valleys and corresponding effective masses with respect to the strain are explored. Finally, the strained MoSi₂N₄ or WSi₂N₄ are used as the channel of a p-type FET and the corresponding current–voltage characteristic is explored. The results show that this FET has an ${I}_{ \mathrm{\scriptscriptstyle ON}} / {I}_{ \mathrm{\scriptscriptstyle OFF}}$ ratio larger than 10⁶ and sub-threshold swing (SS) in the range of 96–98 mV/dec. The ${I}_{ \mathrm{\scriptscriptstyle ON}} / {I}_{ \mathrm{\scriptscriptstyle OFF}}$ ratio of these compounds with respect to strain are compared.