Light-induced aluminum plating on silicon for solar cell metallization

A method for processing a silicon solar cell, the method comprising:

• preparing an ionic liquid comprising aluminum chloride (AlCl3) and an organic halide;
• patterning a partially-processed silicon solar cell to expose an n-type surface of a silicon substrate;
• bringing the n-type surface of the silicon substrate of the partially processed silicon solar cell into contact with the ionic liquid, wherein the n-type surface does not comprise a seed layer;
• illuminating the n-type surface, wherein the illumination passes through the ionic liquid, wherein the illumination is generated at least partially by a light source comprising at least one light-emitting diode, and wherein a photo-generated current is generated by the illumination;
• while illuminating the silicon substrate with the light source, applying a current between an anode and a cathode to generate an applied current, wherein the applied current generates a current density of between 30 milliamps per centimeter squared (mA/cm2) and 50 mA/cm2;
• and
• depositing aluminum onto the silicon substrate via a light-induced electroplating process, wherein the light-induced electroplating process utilizes the applied current that does not exceed the photo-generated current generated by the illumination.