Patent ID: 8802970
Filing Date: 2014-08-12
Classification: C03C,H01B,H01L,Y02E,Y02P

Abstract:
1. A method of making a photovoltaic cell comprising: a. providing a silicon wafer having a first side and a second side, b. applying a phosphorus source to the first side of the silicon wafer, c. firing the wafer to form a phosphorus glass layer on the first side of the silicon wafer, d. removing at least a portion of the phosphorus glass layer from the first side of the silicon wafer, e. polishing the second side of the silicon wafer, f. applying a passivating layer to the first and second sides of the wafer, g. applying to the first side a silver paste comprising, prior to firing, h. applying to the second side an aluminum paste comprising, prior to firing, wherein (g) and (h) can be performed in any order, and i. firing the wafer for a time and temperature sufficient to adhere the silver to the front side and the aluminum to the back side, thereby forming front and back contacts.