High efficiency cadmium telluride solar cell and method of fabrication

摘要

A method of forming an ohmic contact and electron reflector on a surface of a CdTe containing compound film as may be found, for example in a photovoltaic cell. The method comprises forming a Cd-deficient, Te-rich surface region at a surface of the CdTe containing compound film; exposing the Cd-deficient surface region to an electron reflector forming material; forming the electron reflector; and laying down a contact layer over the electron reflector layer. The solar cell so produced has a Cd-deficient region which is converted to an electron reflector layer on the surface of a CdTe absorber layer, and an ohmic contact. A Cd/Te molar ratio within the Cd-deficient region decreases from 1 at an interface with the CdTe absorber layer to a value less than 1 towards the ohmic contact.

主权项

1. A method of forming a CdTe solar cell comprising:
depositing a CdTe layer; treating an exposed face of the CdTe layer to form a Cd-deficient surface region, the Cd-deficient surface region having a free surface and an interface with the CdTe layer; exposing the Cd-deficient surface region through its free surface to at least one electron reflector forming species; causing a reaction between the Cd-deficient surface region and the at least one electron reflector forming species to convert the Cd-deficient surface region into an electron reflector layer; and laying down a contact layer on the electron reflector layer; wherein the Cd/Te molar ratio within the Cd-deficient surface region decreases monotonically from 1 at the interface with the CdTe layer to a value less than 1 towards the free surface.