A wire-form emitter metal–insulator–semiconductor tunnel junction

•A cylindrically-symmetrical metal–insulator–semiconductor system is considered.•Voltage partitioning and tunneling current components are theoretically analyzed.•Cylindrical MIS structure behaves, roughly, like a planar one with higher doping.•Quantitative changes vs. a planar case are essential for cylinder radii <0.1 μm.•Similar geometry may be faced with for a quantum-wire emitter or in edge region.

Physical effects arising due to change of configuration of a MIS system from planar to cylindrical, are theoretically analyzed. Attention is paid to the voltage partitioning and all the components of tunneling current. A simple simulation model is developed enabling prediction of the band diagram details and calculation of the currents. The trends expected with decreasing system radius are elucidated. Cylindrical geometry can be faced with when quantum wire is used as an electron emitter. Similar form may also be roughly attributed to an edge region of conventional MIS capacitors.