title: Diameter-dependent internal gain in ZnO micro/nanowires under electron beam irradiation.
abstract: We observed a conductivity gain in intrinsic ZnO micro/nanowires at characteristic diameter scales from nanoscale to microscale by employing metal-semiconductor-metal structures with ohmic contacts under electron beam irradiation. The conductivity is enhanced under electron beam illumination and the magnitude is inversely proportional to the micro/nanowire diameter from 400 nm to 1300 nm at constant radiation intensity. We also introduced a model to simulate the diameter-dependent electric potential distribution. We attribute these observations to the variation of the effective electron carrier density upon varying diameters of ZnO micro/nanowires, as a result of field effects from the diameter-dependent population of the surface-trapped holes.
authors.affiliation: State Key Laboratory for Advanced Metals and Materials, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, People's Republic of China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
authors.forename: Junjie
authors.initials: J
authors.lastname: Qi
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhang