Nanowire Solar Cell: Radial-Junction Light Trapping

Vertical silicon-nanowire arrays with a radial (core–shell) p–n junction let a solar cell absorb light along a long axial path while collecting charge over a short radial one — decoupling two requirements that fight each other in a planar cell. This simulator renders a real 3D nanowire array under a falling stream of photons: each absorption event spawns an electron–hole pair that either diffuses out to the shell junction and gets collected, or recombines before it arrives. Four controls — wire radius, array height, minority-carrier diffusion length and packing fill fraction — drive live formulas for absorption, collection efficiency and relative short-circuit current, so you can see directly why thin, tall, well-spaced nanowires can outperform an equivalent planar absorber.