Visualization of Carrier Depletion in Semiconducting Nanowires

The visualization of the space–charge region in nanowire pn junctions (see image) is presented by far-field optical microscopy. This general approach is a powerful tool for estimates of the carrier distributions and device capacitances. For the case of an n-CdS/p+-Si heterojunction we show that the carrier depletion widths in nanowires deviate from the traditional square-root dependence purely due to electrostatic effects.