title: Current saturation in field emission from H-passivated Si nanowires.
abstract: This paper explores the field emission (FE) properties of highly crystalline Si nanowires (NWs) with controlled surface passivation. The NWs were batch-grown by the vapor-liquid-solid process using Au catalysts with no intentional doping. The FE current-voltage characteristics showed quasi-ideal current saturation that resembles those predicted by the basic theory for emission from semiconductors, even at room temperature. In the saturation region, the currents were extremely sensitive to temperature and also increased linearly with voltage drop along the nanowire. The latter permits the estimation of the doping concentration and the carrier lifetime, which is limited by surface recombination. The conductivity could be tuned over 2 orders of magnitude by in situ hydrogen passivation/desorption cycles. This work highlights the role of dangling bonds in surface leakage currents and demonstrates the use of hydrogen passivation for optimizing the FE characteristics of Si NWs.
authors: Département de chimie, Université de Montréal, Montréal, Québec H3T 1J4, Canada.
authors: May
authors: M
authors: Choueib
authors: Richard
authors: R
authors: Martel
authors: Costel Sorin
authors: CS
authors: Cojocaru
authors: Anthony
authors: A
authors: Ayari
authors: Pascal
authors: P
authors: Vincent
authors: Stephen T
authors: ST
authors: Purcell
mesh_terms: D003460:Crystallization / Q000379:methods*; D004553:Electric Conductivity; D004579:Electron Transport; D006859:Hydrogen / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D006859:Hydrogen; D012825:Silicon