Patent ID: 9722106
Date: 2017-08-01
CPC Classifications: B23K,H01L,Y02E,Y02P

Claim:
1. A method of manufacturing a solar cell having a front face and a back, opposing face, the solar cell including a silicon substrate having a first surface proximate to the front face and a second, opposing surface distal from the front face, and the method comprising: providing a dielectric stack having first and second opposing surfaces, wherein the first surface of the dielectric stack is deposited in direct contact with the second surface of the silicon substrate, and the dielectric stack comprises at least a first dielectric layer comprising Aluminum Oxide (AlOx) and a second dielectric layer, each of the first dielectric layer and the second dielectric layer comprising an associated top surface and a bottom, opposing surface, wherein the top surface of the first dielectric layer is the first surface of the dielectric stack and the top surface of the second dielectric layer is deposited in direct contact with the bottom surface of the first dielectric layer; removing portions of the second dielectric layer to form at least one partial opening in the dielectric stack in a manner such that at least a continuous portion of the first dielectric layer remains at locations of the dielectric stack in which the at least one partial openings are formed such that the first dielectric layer covers the entire second surface of said substrate; wherein the at least one partial opening in the dielectric stack is formed through a partial laser ablation process in which portions of the second dielectric layer are substantially completely ablated while the first dielectric layer is only partially ablated; wherein the thickness of the first dielectric layer after partial ablation at the at least one partial opening is between 1 nanometer (nm) and 30 nm; and providing one or more metal contacts on the back face of the solar cell on the partially ablated first dielectric layer.