NOVELTY - Forming doped Group IBIIIAVIA absorber layer (202) on base (104) involves depositing precursor layer on base, where the precursor layer comprises Group IB/Group IIIA/Group VIA material films and dopant material film; annealing precursor layer on base to form doped Group IBIIIAVIA absorber layer; interrupting annealing of precursor layer to remove some dopant from exposed surface of absorber layer; and annealing precursor layer to continue to form doped Group IBIIIAVIA absorber following removal of some dopant from exposed surface.    USE - For forming doped Group IBIIIAVIA absorber layer on base, which is used in solar cell (claimed), particularly copper indium gallium diselenide (CIGS) based solar cells, and photovoltaic cells.    ADVANTAGE - The obtained doped Group IBIIIAVIA absorber layer provides greatest potential for high performance, high efficiency, and low cost thin film photovoltaic products.    DETAILED DESCRIPTION - Forming a doped Group IBIIIAVIA absorber layer (202) for a solar cell on a base (104), involves: depositing a precursor layer on the base, where the precursor layer comprises a Group IB material film, a Group IIIA material film, a Group VIA material film and a dopant material film; annealing the precursor layer on the base to form the doped Group IBIIIAVIA absorber layer, where the annealing of the precursor layer induces diffusion of the dopant to an exposed surface of the absorber layer; interrupting the annealing of the precursor layer to remove at least some of the dopant from the exposed surface of the absorber layer, where the step of removing the dopant includes applying a liquid including water and having a pH of 1-4, to remove at least some of the dopant; and annealing the precursor layer to continue to form the doped Group IBIIIAVIA absorber following removal of at least some of the dopant from the exposed surface. The step of depositing the precursor layer involves depositing a metallic stack including at least one Cu film, In film and Ga film; depositing the dopant material film over the metallic stack; and depositing a first Se film on the dopant material film.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic side view of a semi-reacted CIGS absorber layer including a dopant rich segregation layer positioned on it, where the semi-reacted CIGS absorber layer has been formed by annealing the CIGS absorber precursor.    Base (104)    Substrate (106)    Conductive contact layer (108)    Doped Group IBIIIAVIA absorber layer (202)    Dopant rich layer (203)