Abstract: Another aspect of the present disclosure relates to a device including a substrate, having a top surface and a bottom surface; an array of nanowires having a base and a top surface, the base contacting the top surface of the substrate; a contacting structure including the same material as the substrate having a non-nanostructured surface of a dimension suitable for forming an electrical contact, located on the same side of the substrate as the array of silicon nanowires; wherein the contacting structure is doped with a greater impurity concentration than the nanowire array, thereby forming a selective emitter.

Abstract: A process is provided for etching a silicon-containing substrate to form nanowire arrays. In this process, one deposits nanoparticles and a metal film onto the substrate in such a way that the metal is present and touches silicon where etching is desired and is blocked from touching silicon or not present elsewhere. One submerges the metallized substrate into an etchant aqueous solution comprising HF and an oxidizing agent. In this way arrays of nanowires with controlled diameter and length are produced.

Abstract: A process for etching a silicon-containing substrate to form structures is provided. In the process, a metal is deposited and patterned onto a silicon-containing substrate (commonly one with a resistivity above 1-10 ohm-cm) in such a way that the metal is present and touches silicon where etching is desired and is blocked from touching silicon or not present elsewhere. The metallized substrate is submerged into an etchant aqueous solution comprising about 4 to about 49 weight percent HF and an oxidizing agent such as about 0.5 to about 30 weight percent H2O2, thus producing a metallized substrate with one or more trenches. A second silicon etch is optionally employed to remove nanowires inside the one or more trenches.

Abstract: A photovoltaic device is provided. It comprises at least two electrical contacts, p type dopants and n type dopants. It also comprises a bulk region and nanowires in an aligned array which contact the bulk region. All nanowires in the array have one predominant type of dopant, n or p, and at least a portion of the bulk region also comprises that predominant type of dopant. The portion of the bulk region comprising the predominant type of dopant typically contacts the nanowire array. The photovoltaic devices' p-n junction would then be found in the bulk region. The photovoltaic devices would commonly comprise silicon.

Abstract: A photovoltaic device is provided. It comprises at least two electrical contacts, p type dopants and n type dopants. It also comprises a bulk region and nanowires in an aligned array which contact the bulk region. All nanowires in the array have one predominant type of dopant, n or p, and at least a portion of the bulk region also comprises that predominant type of dopant. The portion of the bulk region comprising the predominant type of dopant typically contacts the nanowire array. The photovoltaic devices' p-n junction would then be found in the bulk region. The photovoltaic devices would commonly comprise silicon.

Abstract: A process is provided for etching a silicon-containing substrate to form nanowire arrays. In this process, one deposits nanoparticles and a metal film onto the substrate in such a way that the metal is present and touches silicon where etching is desired and is blocked from touching silicon or not present elsewhere. One submerges the metallized substrate into an etchant aqueous solution comprising HF and an oxidizing agent. In this way arrays of nanowires with controlled diameter and length are produced.

Abstract: In one aspect, the present disclosure relates to a device including a substrate, having a top surface and a bottom surface; an array of nanowires having a base and a top surface, the base contacting the top surface of the substrate; a contacting structure having a non-nanostructured surface, having a top surface and a bottom surface, located on the same side of the substrate as the array of silicon nanowires; and an electrical contact in contact with the top surface of the contacting structure. In some embodiments, the device includes an aluminum oxide passivation layer over the array of nanowires. In some embodiments, the layer of aluminum oxide is deposited via atomic layer deposition.

Abstract: In one aspect, the present disclosure relates to a device including a silicon substrate, wherein at least a portion of the substrate surface can be a silicon nanowire array; and a layer of alumina covering the silicon nanowire array. In some embodiments, the device can be a solar cell. In some embodiments, the device can be a p-n junction. In some embodiments, the p-n junction can be located below the bottom surface the nanowire array.

Abstract: Another aspect of the present disclosure relates to a device including a substrate, having a top surface and a bottom surface; an array of nanowires having a base and a top surface, the base contacting the top surface of the substrate; a contacting structure including the same material as the substrate having a non-nanostructured surface of a dimension suitable for forming an electrical contact, located on the same side of the substrate as the array of silicon nanowires; wherein the contacting structure is doped with a greater impurity concentration than the nanowire array, thereby forming a selective emitter.

Abstract: A process is provided for etching a silicon-containing substrate. In the process, the surface of the substrate is cleaned. A film of alumina is deposited on the cleaned substrate surface. A silver film is deposited above the film of alumina. An etchant comprising HF is contacted with the silver film.

Abstract: A process is provided for etching a silicon-containing substrate to form nanowire arrays. In this process, one deposits nanoparticles and a metal film onto the substrate in such a way that the metal is present and touches silicon where etching is desired and is blocked from touching silicon or not present elsewhere. One submerges the metallized substrate into an etchant aqueous solution comprising HF and an oxidizing agent. In this way arrays of nanowires with controlled diameter and length are produced.

Abstract: In an aspect of the invention, a process to make a nanowire array is provided. In the process, silicon is deposited onto a conductive substrate comprising an organic material and optionally a conductive layer, thus forming a silicon-containing layer. Nanoparticles are deposited on top of the silicon-containing layer. Metal is deposited on top of the nanoparticles and silicon in such a way that the metal is present and touches silicon where etching is desired and is blocked from touching silicon or not present elsewhere. The metallized substrate is contacted with an etchant aqueous solution comprising about 2 to about 49 weight percent HF and an oxidizing agent.

Abstract: A photovoltaic device is provided. It comprises at least two electrical contacts, p type dopants and n type dopants. It also comprises a bulk region and nanowires in an aligned array which contact the bulk region. All nanowires in the array have one predominant type of dopant, n or p, and at least a portion of the bulk region also comprises that predominant type of dopant. The portion of the bulk region comprising the predominant type of dopant typically contacts the nanowire array. The photovoltaic devices' p-n junction would then be found in the bulk region. The photovoltaic devices would commonly comprise silicon.

Abstract: A process for etching a silicon-containing substrate to form structures is provided. In the process, a metal is deposited and patterned onto a silicon-containing substrate (commonly one with a resistivity above 1-10 ohm-cm) in such a way that the metal is present and touches silicon where etching is desired and is blocked from touching silicon or not present elsewhere. The metallized substrate is submerged into an etchant aqueous solution comprising about 4 to about 49 weight percent HF and an oxidizing agent such as about 0.5 to about 30 weight percent H2O2, thus producing a metallized substrate with one or more trenches. A second silicon etch is optionally employed to remove nanowires inside the one or more trenches.

Abstract: A process is provided for etching a silicon-containing substrate to form nanowire arrays. In this process, one deposits nanoparticles and a metal film onto the substrate in such a way that the metal is present and touches silicon where etching is desired and is blocked from touching silicon or not present elsewhere. One submerges the metallized substrate into an etchant aqueous solution comprising HF and an oxidizing agent. In this way arrays of nanowires with controlled diameter and length are produced.

Abstract: An aqueous developing solution useful in developing positive-working photoresists comprising:______________________________________ A. Soluble Alkali Metal Phosphate 1.50-3.00% by weight B. Soluble Alkali Metal Silicate 1.00-2.00% by weight C. Mono (lower alkanol) amine 0.40-5.00% by weight D. Soluble Alkylene Glycol 0.25-3.00% by weight E. Lower Alkanol 0.05-1.00% by weight F.