Two-dimensional dopant profiling in POCl3-diffused n+ emitter of textured silicon solar cells

We investigated two-dimensional dopant distribution in POCl
₃
-diffused n+ emitter formed on textured Si solar cells using transmission electron microscopy (TEM) combined with selective chemical etching. TEM and simulation results demonstrate that convex and concave regions of a pyramid in the textured Si surface show deeper and shallower junctions, respectively. By considering a strong dependency of phosphorus (P) diffusion on the Si interstitials, the abnormal profile of n+ emitter in the textured Si surface could be attributed to the inhomogeneous distribution of Si interstitials caused by the geometry of the pyramid texture.