Patent ID: 9537041
Date: 2017-01-03
CPC Classifications: H01L,Y02E,Y02P

Claim:
1. A method of forming emitters for a back-contact solar cell, the method comprising: forming a stack of at least two dopant material source layers above a substrate of the solar cell, wherein a dopant material source layer of the at least two dopant material source layers has dopants of one impurity conductivity type being of opposite polarity from dopants of another impurity conductivity type of an adjacent dopant material source layer of the at least two dopant material source layers; and directing a first laser beam on a first portion of the stack of at least two dopant material source layers to form a single dopant material source layer from the at least two dopant material source layers; wherein directing a first laser beam on a first portion of the stack of at least two dopant material source layers further comprises: patterning with the first laser beam the substrate to form a first emitter of the solar cell from the dopants of one impurity conductivity type that are available in the single dopant material source layer; and further comprising: directing a second laser beam on a region of the first portion of the stack of at least two dopant material source layers to diffuse the dopants of one impurity conductivity type at a second dopant concentration level by using the second laser beam, wherein the second dopant concentration level is greater than the first dopant concentration level.