CRYSTALLINE SILICON PV CELL WITH SELECTIVE EMITTER PRODUCED WITH LOW TEMPERATURE PRECISION ETCH BACK AND PASSIVATION PROCESS

摘要

A method of forming a selective emitter in a photovoltaic (PV) crystalline silicon semiconductor wafer involves forming a mask on a front side surface of the wafer to create masked and unmasked areas on the front side surface. A first silicon oxide layer is electrochemically formed at the unmasked areas of the front side surface such that the silicon oxide layer extends into an emitter of the wafer at least as far as a dead zone therein. The mask is removed and the first silicon oxide layer is etched back until substantially all of the first silicon oxide layer is removed. A second silicon oxide layer is then electrochemically formed on the front side surface such that the second silicon oxide layer has sufficient thickness to passivate the front side surface.