Abnormal Dopant Distribution in $\hbox{POCl}_{3}$ -Diffused $\hbox{N}^{+}$ Emitter of Textured Silicon Solar Cells

We investigated 2-D dopant distribution in a -diffused emitter formed on textured Si solar cells using transmission electron microscopy (TEM) combined with selective chemical etching. TEM and simulation results demonstrate that the convex and concave regions of a pyramid in the textured Si surface show deeper and shallower junctions, respectively. By considering a strong dependence of phosphorus (P) diffusion on the Si interstitials, the abnormal profile of emitter in the textured Si surface could be attributed to the inhomogeneous distribution of Si interstitials caused by the geometry of the pyramid texture.