Solar cell having doped buffer layer and method of fabricating the solar cell

A method comprising:

• forming a single buffer layer of a first CdS material directly on an absorber layer of a photovoltaic device by a non-chemical-bath-deposition (CBD) process from the group consisting of atomic layer deposition, sputtering, electro-deposition, evaporation or chemical vapor deposition;
• extrinsically doping the single buffer layer in a metal organic chemical vapor deposition (MOCVD) chamber;
• and
• forming a front contact layer of a second material directly on the single buffer layer in the same MOCVD chamber, the CdS material extending from an interface between the buffer layer and the absorber layer to an interface between the buffer layer and the front contact layer, the second material having a different composition from the CdS material.

A method comprising:

• forming a single buffer layer of CdS directly on an absorber layer of a photovoltaic device;
• annealing the single buffer layer in a metal organic chemical vapor deposition (MOCVD) chamber having an atmosphere containing B2H6 after the forming step, so as to have a higher concentration of boron dopant at a top surface of the single buffer layer than at an interface between the single buffer layer and the absorber layer;
• and
• forming a front contact layer of a transparent conductive oxide directly on the single buffer layer in the same MOCVD chamber where the annealing is performed, so the CdS extends from the interface between the buffer layer and the absorber layer to an interface between the buffer layer and the front contact layer.