1. A light emitting transistor, comprising: a gate electrode for providing a gate field; a first electrode, wherein the first electrode comprises a dilute nanotube network; a dielectric layer interposed between the gate electrode and the first electrode, a second electrode for injecting a complementary charge to that injected by the first electrode; and an electroluminescent semiconductor layer disposed intermediate the first and second electrodes, wherein the complementary charges combine to produce photons and wherein charge injection between the first electrode and the electroluminescent semiconductor layer is modulated by the gate field.