Abstract: Photovoltaic structures having multiple absorber layers separated by a diffusion barrier are provided. In one aspect, a method of forming an absorber on a substrate includes: depositing a first layer of light absorbing material on the substrate; depositing a diffusion barrier; depositing a second layer of light absorbing material on the diffusion barrier, wherein the first layer of light absorbing material has a different band gap from the second layer of light absorbing material; and annealing the absorber, wherein the diffusion barrier prevents diffusion of elements between the first layer of light absorbing material and the second layer of light absorbing material during the annealing. A solar cell and method for formation thereof are also provided.

Abstract: Improved high work function back contacts for solar cells are provided. In one aspect, a method of forming a solar cell includes: forming a completed solar cell having a substrate coated with an electrically conductive material, an absorber disposed on the electrically conductive material, a buffer layer disposed on the absorber, a transparent front contact disposed on the buffer layer, and a metal grid disposed on the transparent front contact; removing the substrate and the electrically conductive material using exfoliation, exposing a backside surface of the solar cell; depositing a high work function material onto the back side surface of the solar cell; and depositing a back contact onto the high work function material. A solar cell formed by the present techniques is also provided. Yield of the exfoliated device can be improved by removing bubbles from adhesive used for exfoliation and/or forming contact pads to access the metal grid.

Abstract: An integrated kesterite (e.g., CZT(S,Se)) photovoltaic device and battery is provided. In one aspect, a method of forming an integrated photovoltaic device and battery includes: forming a photovoltaic device having a substrate, an electrically conductive layer, an absorber layer, a buffer layer, a transparent front contact, and a metal grid; removing the substrate and the electrically conductive layer from the photovoltaic device to expose a backside surface of the absorber layer; forming at least one back contact on the backside surface of the absorber layer; and integrating the photovoltaic device with a battery, wherein the integrating includes connecting i) a positive contact of the battery with the back contact on the backside surface of the absorber layer and ii) a negative contact of the battery with the metal grid on the transparent front contact. An integrated photovoltaic device and battery is also provided.

Abstract: A photovoltaic device with increased efficiency and a method for making the same. The present invention provides a photovoltaic device including: a transparent substrate; a transparent conductive electrode layer disposed on the transparent substrate; an n-type layer disposed on the transparent conductive electrode layer; a chalcogen absorber layer disposed on the n-type layer; a p-type molybdenum trioxide (MoO3) interlayer disposed on the chalcogen absorber layer; and a conductive layer disposed on the interlayer. A photovoltaic device having a superstrate configuration with the order of the layers reversed is also provided. The present invention further provides methods for making the photovoltaic devices according to the present invention.

Abstract: Silver-containing absorbers for photovoltaic devices and techniques for fabrication thereof are provided. In one aspect, a method of forming an ink includes: mixing a silver halide and a solvent to form a first solution; mixing a metal, sulfur, and the solvent to form a second solution; combining the first solution and the second solution to form a precursor solution; and adding constituent components for an absorber material to the precursor solution to form the ink. Methods of forming an absorber film, a photovoltaic device, and the resulting photovoltaic device are also provided.

Abstract: Kesterite photovoltaic devices having a back surface field layer are provided. In one aspect, a method of forming a photovoltaic device includes: forming a complete photovoltaic device having a substrate, an electrically conductive layer on the substrate, an absorber layer on the electrically conductive layer, a buffer layer on the absorber layer, and a transparent front contact on the buffer layer; removing the substrate and the electrically conductive layer from the complete photovoltaic device to expose a backside surface of the absorber layer; forming a passivating layer on the backside surface of the absorber layer; and forming a high work function back contact on the passivating layer. A photovoltaic device having a passivating layer is also provided.

Abstract: Improved high work function back contacts for solar cells are provided. In one aspect, a method of forming a solar cell includes: forming a completed solar cell having a substrate coated with an electrically conductive material, an absorber disposed on the electrically conductive material, a buffer layer disposed on the absorber, a transparent front contact disposed on the buffer layer, and a metal grid disposed on the transparent front contact; removing the substrate and the electrically conductive material using exfoliation, exposing a backside surface of the solar cell; depositing a high work function material onto the back side surface of the solar cell; and depositing a back contact onto the high work function material. A solar cell formed by the present techniques is also provided. Yield of the exfoliated device can be improved by removing bubbles from adhesive used for exfoliation and/or forming contact pads to access the metal grid.

Abstract: Improved high work function back contacts for solar cells are provided. In one aspect, a method of forming a solar cell includes: forming a completed solar cell having a substrate coated with an electrically conductive material, an absorber disposed on the electrically conductive material, a buffer layer disposed on the absorber, a transparent front contact disposed on the buffer layer, and a metal grid disposed on the transparent front contact; removing the substrate and the electrically conductive material using exfoliation, exposing a backside surface of the solar cell; depositing a high work function material onto the back side surface of the solar cell; and depositing a back contact onto the high work function material. A solar cell formed by the present techniques is also provided. Yield of the exfoliated device can be improved by removing bubbles from adhesive used for exfoliation and/or forming contact pads to access the metal grid.

Abstract: A method of fabricating a photovoltaic device includes performing fabrication operations to form the photovoltaic device. The fabrication operations include replacing a portion of selenium with sulfur in a copper zinc tin sulfur selenium alloy (CZTSSe) material arranged on a substrate to form a sulfur enriched CZTSSe material to alter a band gap of the CZTSSe material. The fabrication operations include removing surface secondary phases or degraded portions of the sulfur enriched CZTSSe material to form a single phase sulfur enriched CZTSSe material. The fabrication operations further include replacing the substrate in contact with the single phase sulfur enriched CZTSSe material with a different contact material to form an exfoliated sulfur enriched CZTSSe device.

Abstract: An integrated kesterite (e.g., CZT(S,Se)) photovoltaic device and battery is provided. In one aspect, a method of forming an integrated photovoltaic device and battery includes: forming a photovoltaic device having a substrate, an electrically conductive layer, an absorber layer, a buffer layer, a transparent front contact, and a metal grid; removing the substrate and the electrically conductive layer from the photovoltaic device to expose a backside surface of the absorber layer; forming at least one back contact on the backside surface of the absorber layer; and integrating the photovoltaic device with a battery, wherein the integrating includes connecting i) a positive contact of the battery with the back contact on the backside surface of the absorber layer and ii) a negative contact of the battery with the metal grid on the transparent front contact. An integrated photovoltaic device and battery is also provided.

Abstract: Photovoltaic structures having multiple absorber layers separated by a diffusion barrier are provided. In one aspect, a method of forming an absorber on a substrate includes: depositing a first layer of light absorbing material on the substrate; depositing a diffusion barrier; depositing a second layer of light absorbing material on the diffusion barrier, wherein the first layer of light absorbing material has a different band gap from the second layer of light absorbing material; and annealing the absorber, wherein the diffusion barrier prevents diffusion of elements between the first layer of light absorbing material and the second layer of light absorbing material during the annealing. A solar cell and method for formation thereof are also provided.

Abstract: An integrated kesterite (e.g., CZT(S,Se)) photovoltaic device and battery is provided. In one aspect, a method of forming an integrated photovoltaic device and battery includes: forming a photovoltaic device having a substrate, an electrically conductive layer, an absorber layer, a buffer layer, a transparent front contact, and a metal grid; removing the substrate and the electrically conductive layer from the photovoltaic device to expose a backside surface of the absorber layer; forming at least one back contact on the backside surface of the absorber layer; and integrating the photovoltaic device with a battery, wherein the integrating includes connecting i) a positive contact of the battery with the back contact on the backside surface of the absorber layer and ii) a negative contact of the battery with the metal grid on the transparent front contact. An integrated photovoltaic device and battery is also provided.

Abstract: A method of restricting diffusion of miscible materials across a barrier, including, forming a 2-dimensional material on a substrate surface, wherein the 2-dimensional material includes one or more defects through which a portion of the substrate surface is exposed, forming a plug selectively on the exposed substrate surface, and forming a cover layer on the plug and 2-dimensional material, wherein the cover layer material is miscible in the substrate material.

Abstract: Photovoltaic structures having multiple absorber layers separated by a diffusion barrier are provided. In one aspect, a method of forming an absorber on a substrate includes: depositing a first layer of light absorbing material on the substrate; depositing a diffusion barrier; depositing a second layer of light absorbing material on the diffusion barrier, wherein the first layer of light absorbing material has a different band gap from the second layer of light absorbing material; and annealing the absorber, wherein the diffusion barrier prevents diffusion of elements between the first layer of light absorbing material and the second layer of light absorbing material during the annealing. A solar cell and method for formation thereof are also provided.

Abstract: Silver-containing absorbers for photovoltaic devices and techniques for fabrication thereof are provided. In one aspect, a method of forming an ink includes: mixing a silver halide and a solvent to form a first solution; mixing a metal, sulfur, and the solvent to form a second solution; combining the first solution and the second solution to form a precursor solution; and adding constituent components for an absorber material to the precursor solution to form the ink. Methods of forming an absorber film, a photovoltaic device, and the resulting photovoltaic device are also provided.

Abstract: Silver-containing absorbers for photovoltaic devices and techniques for fabrication thereof are provided. In one aspect, a method of forming an ink includes: mixing a silver halide and a solvent to form a first solution; mixing a metal, sulfur, and the solvent to form a second solution; combining the first solution and the second solution to form a precursor solution; and adding constituent components for an absorber material to the precursor solution to form the ink. Methods of forming an absorber film, a photovoltaic device, and the resulting photovoltaic device are also provided.

Abstract: A method of restricting diffusion of miscible materials across a barrier, including, forming a 2-dimensional material on a substrate surface, wherein the 2-dimensional material includes one or more defects through which a portion of the substrate surface is exposed, forming a plug selectively on the exposed substrate surface, and forming a cover layer on the plug and 2-dimensional material, wherein the cover layer material is miscible in the substrate material.

Abstract: Kesterite photovoltaic devices having a back surface field layer are provided. In one aspect, a method of forming a photovoltaic device includes: forming a complete photovoltaic device having a substrate, an electrically conductive layer on the substrate, an absorber layer on the electrically conductive layer, a buffer layer on the absorber layer, and a transparent front contact on the buffer layer; removing the substrate and the electrically conductive layer from the complete photovoltaic device to expose a backside surface of the absorber layer; forming a passivating layer on the backside surface of the absorber layer; and forming a high work function back contact on the passivating layer. A photovoltaic device having a passivating layer is also provided.

Abstract: A method of restricting diffusion of miscible materials across a barrier, including, forming a 2-dimensional material on a substrate surface, wherein the 2-dimensional material includes one or more defects through which a portion of the substrate surface is exposed, forming a plug selectively on the exposed substrate surface, and forming a cover layer on the plug and 2-dimensional material, wherein the cover layer material is miscible in the substrate material.

Abstract: Improved high work function back contacts for solar cells are provided. In one aspect, a method of forming a solar cell includes: forming a completed solar cell having a substrate coated with an electrically conductive material, an absorber disposed on the electrically conductive material, a buffer layer disposed on the absorber, a transparent front contact disposed on the buffer layer, and a metal grid disposed on the transparent front contact; removing the substrate and the electrically conductive material using exfoliation, exposing a backside surface of the solar cell; depositing a high work function material onto the back side surface of the solar cell; and depositing a back contact onto the high work function material. A solar cell formed by the present techniques is also provided. Yield of the exfoliated device can be improved by removing bubbles from adhesive used for exfoliation and/or forming contact pads to access the metal grid.