Magnesium fluoride based electron-selective contact

Abstract

This work demonstrates a simple process for fabricating an electron-selective contact with a contact resistivity of 76 mΩ·cm2 and a contact recombination current density of 10 fA/cm2 on n-type crystalline silicon. The contact is facilitated via an amorphous silicon (∼ 6.5 nm) / magnesium fluoride (∼ 1 nm) / aluminium stack. The application of this novel electron-selective contact enables fabrication of a 20.1%-efficient n-type front-junction silicon solar cell. This contact is made to the full area of the rear surface, omitting the need for (i) high-temperature phosphorus diffusion, and (ii) patterning of the rear dielectrics by photolithography or laser processing.