tetralayer

tetra- +‎ layer

tetralayer (plural tetralayers)

1. A structure composed of four layers
   • 2015, Ignacio Gutiérrez-Lezama, Ashish Arora, Alberto Ubaldini, Céline Barreteau, Enrico Giannini, Marek Potemski, Alberto F. Morpurgo, “Indirect-to-direct band-gap crossover in few-layer MoTe${\displaystyle _{2}}$”, in Nano Lett.‎, volume 2015:

     A quantitative analysis of this behavior and of all our experimental observations is fully consistent with mono and bilayer MoTe${\displaystyle _{2}}$ being direct band-gap semiconductors, with tetralayer MoTe${\displaystyle _{2}}$ being an indirect gap semiconductor, and with trilayers having nearly identical direct and indirect gaps.This conclusion is different from the one reached for other recently investigated semiconducting transition metal dichalcogenides, for which only monolayers are found to be direct band-gap semiconductors, with thicker layers having indirect band gaps that are significantly smaller, by hundreds of meV, than the direct gap.