▎ 摘　　要

NOVELTY - A junction transistor comprises emitter layer on substrate, collector layer, and base layer consists of graphene layer, wherein emitter barrier layer is arranged between base layer and emitter layer, collector barrier layer is arranged between base and collector layers and adjacent to graphene layer, and collector barrier layer is compositionally graded material layer which has an electron affinity that decreases in direction pointing from base layer to collector layer. USE - A junction transistor (claimed). ADVANTAGE - Junction transistor has high collector current, low base currents, and high output power, high transparency is provided to electrons, and formation of tunneling barrier for electrons is avoided. DESCRIPTION OF DRAWING(S) - The drawings show the valence and conduction band profile of a junction transistor having a compositionally graded collector barrier layer in absence and under application of an operating voltage.