A photovoltaic device is presented. The photovoltaic device includes a buffer layer disposed on a transparent conductive oxide layer; a window layer disposed on the buffer layer; and an interlayer interposed between the transparent conductive oxide layer and the window layer. The interlayer includes a metal species, wherein the metal species includes gadolinium, beryllium, calcium, barium, strontium, scandium, yttrium, hafnium, cerium, lutetium, lanthanum, or combinations thereof. A method of making a photovoltaic device is also presented

A photovoltaic device is presented. The photovoltaic device includes a buffer layer disposed on a transparent conductive oxide layer; a window layer disposed on the buffer layer; and an interlayer interposed between the transparent conductive oxide layer and the window layer. The interlayer includes a metal species, wherein the metal species includes gadolinium, beryllium, calcium, barium, strontium, scandium, yttrium, hafnium, cerium, lutetium, lanthanum, or combinations thereof. A method of making a photovoltaic device is also presented

A solar cell includes a doped CdTe layer; a graphene layer over the CdTe layer; and metal contacts over the graphene layer. Advantageously, the metal contacts are composed of Pt or MoO.sub.3-x. The doped CdTe layer can be composed of a p-doped CdTe layer, and the solar cell comprises an n-doped CdS layer beneath the CdTe layer. The solar cell can include a conducting oxide layer beneath the CdS layer. The conducting oxide layer can be composed of SnO.sub.2:F. The solar cell can include a glass layer beneath the conducting oxide layer. The graphene contacting the MoO contacts particularly alleviates the issue of the inability of prior CdTe solar cells to collect holes and could increase efficiency by about 5%.

A solar cell includes a doped CdTe layer; a graphene layer over the CdTe layer; and metal contacts over the graphene layer. Advantageously, the metal contacts are composed of Pt or MoO.sub.3-x. The doped CdTe layer can be composed of a p-doped CdTe layer, and the solar cell comprises an n-doped CdS layer beneath the CdTe layer. The solar cell can include a conducting oxide layer beneath the CdS layer. The conducting oxide layer can be composed of SnO.sub.2:F. The solar cell can include a glass layer beneath the conducting oxide layer. The graphene contacting the MoO contacts particularly alleviates the issue of the inability of prior CdTe solar cells to collect holes and could increase efficiency by about 5%.

Designs of extremely high efficiency solar cells are described. A novel alternating bias scheme enhances the photovoltaic power extraction capability above the cell band-gap by enabling the extraction of hot carriers. When applied in conventional solar cells, this alternating bias scheme has the potential of more than doubling their yielded net efficiency. When applied in conjunction with solar cells incorporating quantum wells (QWs) or quantum dots (QDs) based solar cells, the described alternating bias scheme has the potential of extending such solar cell power extraction coverage, possibly across the entire solar spectrum, thus enabling unprecedented solar power extraction efficiency. Within such cells, a novel alternating bias scheme extends the cell energy conversion capability above the cell material band-gap while the quantum confinement structures are used to extend the cell energy conversion capability below the cell band-gap. Light confinement cavities are incorporated into the cell structure in order to allow the absorption of the cell internal photo emission, thus further enhancing the cell efficiency.

Designs of extremely high efficiency solar cells are described. A novel alternating bias scheme enhances the photovoltaic power extraction capability above the cell band-gap by enabling the extraction of hot carriers. When applied in conventional solar cells, this alternating bias scheme has the potential of more than doubling their yielded net efficiency. When applied in conjunction with solar cells incorporating quantum wells (QWs) or quantum dots (QDs) based solar cells, the described alternating bias scheme has the potential of extending such solar cell power extraction coverage, possibly across the entire solar spectrum, thus enabling unprecedented solar power extraction efficiency. Within such cells, a novel alternating bias scheme extends the cell energy conversion capability above the cell material band-gap while the quantum confinement structures are used to extend the cell energy conversion capability below the cell band-gap. Light confinement cavities are incorporated into the cell structure in order to allow the absorption of the cell internal photo emission, thus further enhancing the cell efficiency.

In one embodiment, a method for surface passivation for CdTe devices is provided. The method includes adjusting a stoichiometry of a surface of a CdTe material layer such that the surface becomes at least one of stoichiometric or Cd-rich; and reconstructing a crystalline lattice at the surface of the CdTe material layer by annealing the adjusted surface.

In one embodiment, a method for surface passivation for CdTe devices is provided. The method includes adjusting a stoichiometry of a surface of a CdTe material layer such that the surface becomes at least one of stoichiometric or Cd-rich; and reconstructing a crystalline lattice at the surface of the CdTe material layer by annealing the adjusted surface.

Optically transmissive UV solar cells may be coupled to glass substrates, for example windows, in order to generate electricity while still providing suitable optical behavior for the window. The UV solar cells may be utilized to power electrochromic components coupled to the window to adjust or vary the transmissivity of the window. The UV solar cells may utilize a Schottky ZnO/ZnS heterojunction.

Optically transmissive UV solar cells may be coupled to glass substrates, for example windows, in order to generate electricity while still providing suitable optical behavior for the window. The UV solar cells may be utilized to power electrochromic components coupled to the window to adjust or vary the transmissivity of the window. The UV solar cells may utilize a Schottky ZnO/ZnS heterojunction.