Patent ID: 7170001

Claim:
A back-contacted solar cell, comprising: a p-type bulk semiconductor substrate, having a front side and a backside; a front side n + diffusion emitter layer located on the front side of the semiconductor substrate; a n-gridline negative ohmic contact located on the backside of the semiconductor substrate; a solid n ++ doped conductive via disposed through the thickness of the semiconductor substrate that electrically connects the front side n+ emitter layer to the negative ohmic contact located on the backside of the semiconductor substrate; and a p-gridline positive ohmic contact located on the back side of the semiconductor substrate; wherein the conductive via comprises a recrystallized n ++ doped trail that has been formed after a surface-deposited solute material has migrated completely through the semiconductor substrate from one side to the other, driven by a gradient-driven migration process; and wherein the solute material is, or contains, an n ++ dopant material.