A transistor includes one or more channel taps containing a stack consisting at least in part of a semiconductor an interfacial III-VI layered compound and a conductor. The III-VI compound consists primarily of atoms from Groups IIIA-B and from Group VIA of the Periodic Table of the Elements in an approximate 1:1 ratio. These materials may be formed as layers of covalently bonded elements from Groups IIIA-B and covalently bonded Group VIA elements, adjacent and respective planes of which may be bonded by Van der Waals forces (e.g., to form a single bilayer consisting of a single plane of atoms from Groups IIIA-B and a single plane of Group VIA atoms). One particular III-VI material from which the interfacial layer is made, especially for p-channel transistors, is GaSe. Other III-VI compounds, whether pure compounds or alloys of pure compounds, may also be used.