A tunable barrier transistor (100; 200; 200a, 200b), comprising: an inorganic semiconducting layer (102; 203); a source electrode comprising a nano-carbon film (104; 207) having a first portion that is disposed on a portion of a first side of the inorganic semiconducting layer (102; 203), the nano-carbon film (104; 207) forming a source-channel interface with the inorganic semiconducting layer (102; 203), where the nano-carbon film (104; 207) comprises open regions that allow access to the inorganic semiconducting layer (102; 203); a gate dielectric layer (106; 209) having a first side and a second side opposite the first side, the first side disposed on at least the portion of the nano-carbon film (104; 207) of the source electrode that is disposed on the first portion of the first side of the inorganic semiconducting layer (102; 203); a gate electrode (107; 210) disposed on the second side of the gate dielectric layer opposite the nano-carbon film (104; 207), the gate electrode (107; 210) disposed over at least the portion of the nano-carbon film (104; 207) of the source electrode that is disposed on the first portion of the first side of the inorganic semiconducting layer (102; 203), where a gate field produced by the gate electrode (107; 210) accesses the source-channel interface through the open regions of the nano-carbon film (104; 207), and the gate field modulates a barrier height at the source-channel interface, modulates a barrier width and controls an accumulation of carriers in a vicinity of the source-channel interface; characterized in that the tunable barrier transistor (100; 200; 200a, 200b) further comprises: a second dielectric layer (103; 204) disposed on a second portion different from the first portion of the first side of the inorganic semiconducting layer (102; 203), the nano-carbon film (104; 207) extending over at least a portion of a side of the second dielectric layer (103; 204) opposite the inorganic semiconducting layer (102; 203); and a source contact (105; 208) of the source electrode disposed on the second dielectric layer (103; 204), wherein the nano-carbon film (104; 207) of the source electrode is coupled to the source contact (105; 208). an inorganic semiconducting layer (102; 203); a source electrode comprising a nano-carbon film (104; 207) having a first portion that is disposed on a portion of a first side of the inorganic semiconducting layer (102; 203), the nano-carbon film (104; 207) forming a source-channel interface with the inorganic semiconducting layer (102; 203), where the nano-carbon film (104; 207) comprises open regions that allow access to the inorganic semiconducting layer (102; 203); a gate dielectric layer (106; 209) having a first side and a second side opposite the first side, the first side disposed on at least the portion of the nano-carbon film (104; 207) of the source electrode that is disposed on the first portion of the first side of the inorganic semiconducting layer (102; 203); a gate electrode (107; 210) disposed on the second side of the gate dielectric layer opposite the nano-carbon film (104; 207), the gate electrode (107; 210) disposed over at least the portion of the nano-carbon film (104; 207) of the source electrode that is disposed on the first portion of the first side of the inorganic semiconducting layer (102; 203), where a gate field produced by the gate electrode (107; 210) accesses the source-channel interface through the open regions of the nano-carbon film (104; 207), and the gate field modulates a barrier height at the source-channel interface, modulates a barrier width and controls an accumulation of carriers in a vicinity of the source-channel interface; characterized in that the tunable barrier transistor (100; 200; 200a, 200b) further comprises: a second dielectric layer (103; 204) disposed on a second portion different from the first portion of the first side of the inorganic semiconducting layer (102; 203), the nano-carbon film (104; 207) extending over at least a portion of a side of the second dielectric layer (103; 204) opposite the inorganic semiconducting layer (102; 203); and a source contact (105; 208) of the source electrode disposed on the second dielectric layer (103; 204), wherein the nano-carbon film (104; 207) of the source electrode is coupled to the source contact (105; 208). a second dielectric layer (103; 204) disposed on a second portion different from the first portion of the first side of the inorganic semiconducting layer (102; 203), the nano-carbon film (104; 207) extending over at least a portion of a side of the second dielectric layer (103; 204) opposite the inorganic semiconducting layer (102; 203); and a source contact (105; 208) of the source electrode disposed on the second dielectric layer (103; 204), wherein the nano-carbon film (104; 207) of the source electrode is coupled to the source contact (105; 208).