NOVELTY - Solar cell comprises: a layer of p-type group III-nitride alloy (102) for absorbing portion of the solar spectrum upon exposure to light to generate photoexcited electron-hole pairs, where the p-type group III-nitride alloy includes top surface (106a) and bottom surface (106b), and a conduction band and valence band; many structural imperfections within the p-type group III-nitride alloy, where each of the structural imperfections having surface that extends between the top and bottom surfaces of the p-type group III-nitride alloy; and a layer of n-type group III-nitride alloy (120).    USE - Used as a solar cell.    ADVANTAGE - The solar cell has improved ways to separate and collect photoexcited charges; and utilizes lower quality materials, thus reducing manufacturing efforts and costs.    DETAILED DESCRIPTION - Solar cell comprises: a layer of a p-type group III-nitride alloy (102) for absorbing a portion of the solar spectrum upon exposure to light to generate photoexcited electron-hole pairs, where the p-type group III-nitride alloy includes a top surface (106a) and bottom surface (106b), and a conduction band having a conduction band edge and a valence band having a valence band edge with a band gap between the conduction band edge and the valence band edge; many structural imperfections within the p-type group III-nitride alloy, each of the structural imperfections having a surface that extends between the top surface and the bottom surface of the p-type group III-nitride alloy, where a Fermi level stabilization energy (EFs), exists representing a Fermi level pinning position at the surfaces of the structural imperfections; and a layer of n-type group III-nitride alloy (120), where the p-type group III-nitride alloy is compositionally graded along the structural imperfections between at least a first area and a second area of the p-type group III-nitride alloy so that the first area possesses a first composition of the p-type group III-nitride alloy having its conduction band edge beneath the EFs, and the second area possesses a second composition of the p-type group III-nitride alloy having its conduction band edge above the EFs.    DESCRIPTION OF DRAWING(S) - The figure shows a block diagram representation of the layers of a photovoltaic device with three dimensional (3D) charge separation and collection.    Photovoltaic device (100)    p-Type doped group III-nitride layer (102)    Top surface (106a)    Bottom surface (106b)    n-Type group III-nitride layer (120)