Concerning Built-In Potential of a Radial Asymmetrically Doped P-N Heterojunction in Core-Shell Nanowire

This article investigates theoretically electronic properties of radial type 1 p-n heterojunction in core-shell nanowire when doping level of the wide-gap layer is significantly higher than that of the narrow-gap one. The investigation takes into account contribution of excess free minority carriers into space charge of the narrow-gap part of the junction. By example of strongly asymmetric p+- n heterojunction, it is shown that contribution of free minority carriers (as distinct from contribution of free majority ones) results in increase (rather than decrease) in both width of space charge region and built-in potential of the junction. This is important for electronics of photovoltaic devices. Value of the effect depends on p+- n junction radius.