tetralayer

— A quantitative analysis of this behavior and of all our experimental observations is fully consistent with mono and bilayer MoTe#95;2 being direct band-gap semiconductors, with tetralayer MoTe#95;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.