A method for forming a back contact on an absorber layer in a photovoltaic device includes forming a two dimensional material on a first substrate. An absorber layer including CuZnSnS(Se) (CZTSSe) is grown over the first substrate on the two dimensional material. A buffer layer is grown on the absorber layer on a side opposite the two dimensional material. The absorber layer is exfoliated from the two dimensional material to remove the first substrate from a backside of the absorber layer opposite the buffer layer. A back contact is deposited on the absorber layer.

A method and resulting structure of patterning a metal film pattern over a substrate, including forming a metal film pattern over the substrate; depositing a coating over the substrate surface and the metal film pattern; and removing the coating over the metal film pattern by laser irradiation. The substrate and coating do not significantly interact with the laser irradiation, and the laser irradiation interacts with the metal film pattern and the coating, resulting in the removal of the coating over the metal film pattern. The invention offers a technique for the formation of a metal pattern surrounded by a dielectric coating for solar cells, where the dielectric coating may function as an antireflection coating on the front surface, internal reflector on the rear surface, and may further may function as a dielectric barrier for subsequent electroplating of metal patterns on either surface.

Methods of fabricating solar cells using a metal-containing thermal and diffusion barrier layer in foil-based metallization approaches, and the resulting solar cells, are described. For example, a method of fabricating a solar cell includes forming a plurality of semiconductor regions in or above a substrate. The method also includes forming a metal-containing thermal and diffusion barrier layer above the plurality of semiconductor regions. The method also includes forming a metal seed layer on the metal-containing thermal and diffusion barrier layer. The method also includes forming a metal conductor layer on the metal seed layer. The method also includes laser welding the metal conductor layer to the metal seed layer. The metal-containing thermal and diffusion barrier layer protects the plurality of semiconductor regions during the laser welding.

Methods of fabricating solar cell emitter regions with differentiated P-type and N-type regions architectures, and resulting solar cells, are described. In an example, a back contact solar cell includes a substrate having a light-receiving surface and a back surface. A first polycrystalline silicon emitter region of a first conductivity type is disposed on a first thin dielectric layer disposed on the back surface of the substrate. A second polycrystalline silicon emitter region of a second, different, conductivity type is disposed on a second thin dielectric layer disposed on the back surface of the substrate. A third thin dielectric layer is disposed laterally directly between the first and second polycrystalline silicon emitter regions. A first conductive contact structure is disposed on the first polycrystalline silicon emitter region. A second conductive contact structure is disposed on the second polycrystalline silicon emitter region.

Photovoltaic cells, photovoltaic devices, and methods of fabrication are provided. The photovoltaic cells include a transparent substrate to allow light to enter the photovoltaic cell through the substrate, and a light absorption layer associated with the substrate. The light absorption layer has opposite first and second surfaces, with the first surface being closer to the transparent substrate than the second surface. A passivation layer is disposed over the second surface of the light absorption layer, and a plurality of first discrete contacts and a plurality of second discrete contacts are provided within the passivation layer to facilitate electrical coupling to the light absorption layer. A first electrode and a second electrode are disposed over the passivation layer to contact the plurality of first discrete contacts and the plurality of second discrete contacts, respectively. The first and second electrodes include a photon-reflective material.

Thin-film photovoltaic devices and methods of their use and manufacture are disclosed. More particularly, polycrystalline CuIn.sub.(1-x)Ga.sub.xSe.sub.2 (CIGS) based thin-film photovoltaic devices having independently tunable sublayers are disclosed. Also provided are methods of producing an n-doped graphene.

A laser processing system can be utilized to produce high-performance interdigitated back contact (IBC) solar cells. The laser processing system can be utilized to ablate, transfer material, and/or laser-dope or laser fire contacts. Laser ablation can be utilized to remove and pattern openings in a passivated or emitter layer. Laser transferring may then be utilized to transfer dopant and/or contact materials to the patterned openings, thereby forming an interdigitated finger pattern. The laser processing system may also be utilized to plate a conductive material on top of the transferred dopant or contact materials.

Indentation approaches for foil-based metallization of solar cells, and the resulting solar cells, are described. For example, a method of fabricating a solar cell includes forming a plurality of alternating N-type and P-type semiconductor regions in or above a substrate. The method also includes locating a metal foil above the alternating N-type and P-type semiconductor regions. The method also includes forming a plurality of indentations through only a portion of the metal foil, the plurality of indentations formed at regions corresponding to locations between the alternating N-type and P-type semiconductor regions. The method also includes, subsequent to forming the plurality of indentations, isolating regions of the remaining metal foil corresponding to the alternating N-type and P-type semiconductor regions.

A photovoltaic or light detecting device is provided that includes a periodic array of dome or dome-like protrusions at the light impingement surface and three forms of reflector/back electrode at the device back. The beneficial interaction between an appropriately designed top protrusion array and these reflector/electrode back contacts (R/EBCs) serve (1) to refract the incoming light thereby providing photons with an advantageous larger momentum component parallel to the plane of the back (R/EBC) contact and (2) to provide optical impedance matching for the short wavelength incoming light. The reflector/back electrode operates as a back light reflector and counter electrode to the periodic array of dome or dome-like structures. A substrate supports the reflector/back electrode.

The solar cell (1) of the present invention is provided with an n-side electrode (14), a p-side electrode (15), and a photoelectric conversion unit (20) having a first main surface (20a) and a second main surface (20b). The first main surface (20a) includes an n-type surface (20an) and a p-type surface (20ap). The photoelectric conversion unit (20) has a semiconductor substrate (10) and a semiconductor layer (12n). The semiconductor substrate (10) has first and second main surfaces (10b, 10a). The semiconductor layer (12n) is arranged on a portion of the first main surface (10b). The semiconductor layer (12n) constitutes either the n-type surface (20an) or the p-type surface (20ap). The semiconductor layer (12n) includes a relatively thick portion (12n1) and a relative thin portion (12n2). The n-side electrode (14) or the p-side electrode (15) is arranged on at least the relatively thin portion (12n2) of the semiconductor layer (12n). The solar cell of the present invention, by means of the aforementioned configuration, is able to extend the lifetime of the minor carriers by means of the relatively thick portion (12n1), to maintain low resistance between the semiconductor substrate (10) and the n-side electrode (14) by means of the relatively thin portion (12n2), and to increase hole and electron collection efficiency.