Phosphorus ink technology has been demonstrated as a simple and cheap method to realize selective emitter (SE) in crystalline silicon solar cells through mass production by a professional photovoltaic company. It has achieved average conversion efficiency (η) of 19.01% with peak η of 19.27% for the SE solar cells based on commercial-grade p-type silicon substrate, which is much higher than that of the homogeneous emitter counter parts whose average η is 18.56% [63].