A transistor structure includes a first channel layer over a second channel layer, where the first and the second channel layers include a monocrystalline transition metal dichalcogenide (TMD). The transistor structure further includes a source material coupled to a first end of the first and second channel layers, a drain material coupled to a second end of the first and second channel layers, a gate electrode between the source material and the drain material, and between the first channel layer and the second channel layer and a gate dielectric between the gate electrode and each of the first channel layer and the second channel layer.