In one aspect of the present invention, a photovoltaic device is provided. The photovoltaic device includes a window layer and an absorber layer disposed on the window layer, wherein the absorber layer includes a first region and a second region, the first region disposed adjacent to the window layer. The absorber layer further includes a first additive and a second additive, wherein a concentration of the first additive in the first region is greater than a concentration of the first additive in the second region, and wherein a concentration of the second additive in the second region is greater than a concentration of the second additive in the first region. Method of making a photovoltaic device is also provided.