Optical suppression of ionized impurity scattering in vertical hot-electron transport

A striking effect of illumination on the vertical nonequilibrium electron transport has been observed in the GaAs-based tunneling hot electron transfer amplifier (THETA). Weak illumination can considerably increase the transparency of a THETA structure for quasiballistic electrons if the photon energy exceeds the GaAs band gap. The temperature and illumination intensity dependencies indicate that the effect is caused by photoneutralization of ionized impurities which are a major source of hot electron scattering.