Methods of forming a high efficiency solar cell with a localized back surface field

摘要

A solar cell, comprising: a doped silicon substrate, the silicon substrate comprising a front surface and a rear surface; a front phosphorous diffusion layer formed on the front surface; a front anti-reflective layer formed on the front phosphorous diffusion layer; a front metal electrode on the front surface in ohmic contact with the front phosphorous diffusion layer through the front anti-reflective layer; a rear passivation layer formed on the rear surface; a rear metal electrode in a pattern on the rear surface passing through the rear passivation layer; and a rear p+ diffusion area on the rear surface between the rear passivation layer and a boron-doped region of the silicon substrate, the rear p+ diffusion area surrounding the rear metal electrode.

主权项

1. A method of forming a high efficiency solar cell, comprising steps of:
(a) providing a doped silicon substrate, the substrate comprising a front surface and a rear surface; (b) depositing an ink on the rear surface in a pattern, the ink comprising a p-type dopant and a solvent; (c) heating the silicon substrate in a baking ambient to a first temperature and for a first time period in order to remove residual solvent from the deposited ink; (d) heating the silicon substrate in a diffusion ambient to a second temperature and for a second time period in order to diffuse the p-type dopant into the rear surface to form a rear p+ diffusion area on the rear surface; (e) exposing the silicon substrate to a phosphorous deposition ambient at a third temperature for a third time period, wherein a front PSG layer and a front phosphorous diffusion layer are formed on the front surface, and wherein a rear PSG layer and a rear phosphorous diffusion layer are formed on the rear surface; (f) exposing the silicon substrate to an etchant for a third time period, wherein the front PSG layer is removed, and wherein the rear PSG layer is removed; (g) depositing a front anti-reflective layer on the front surface and a rear passivation layer on the rear surface; and (h) forming a front metal electrode on the front surface in ohmic contact with the front phosphorous diffusion layer through the front anti-reflective layer and a rear metal electrode on the rear surface through the rear passivation layer, the rear metal electrode being formed on the rear p+ diffusion area on the rear surface.