The present invention is a method for manufacturing a substrate for a solar cell composed of a single crystal silicon, including the steps of: producing a silicon single crystal ingot; slicing a silicon substrate from the silicon single crystal ingot; and subjecting the silicon substrate to low temperature thermal treatment at a temperature of 800° C. or more and less than 1200° C., wherein the silicon single crystal ingot or the silicon substrate is subjected to high temperature thermal treatment at a temperature of 1200° C. or more for 30 seconds or more before the low temperature thermal treatment. As a result, it is possible to provide a method for manufacturing a substrate for a solar cell that can prevent decrease in the minority carrier lifetime of the substrate even when the substrate has higher oxygen concentration.

A method for manufacturing a carbon-doped silicon single crystal wafer, including steps of: preparing a silicon single crystal wafer not doped with carbon; performing a first RTA treatment on the silicon single crystal wafer in an atmosphere containing compound gas; performing a second RTA treatment at a higher temperature than the first RTA treatment; cooling the silicon single crystal wafer after the second RTA treatment; and performing a third RTA treatment. The crystal wafer is modified to a carbon-doped silicon single crystal wafer, sequentially from a surface thereof: a 3C-SiC single crystal layer; a carbon precipitation layer; a diffusion layer of interstitial carbon and silicon; and a diffusion layer of vacancy and carbon. A carbon-doped silicon single crystal wafer having a surface layer with high carbon concentration and uniform carbon concentration distribution to enable wafer strength enhancement; and a method for manufacturing the carbon-doped silicon single crystal wafer.

Some examples herein provide a method of forming a doped silicon germanium layer. The method may include simultaneously exposing a substrate to (a) a silicon precursor, (b), a germanium precursor, (c) a boron precursor, and (d) a heteroleptic gallium precursor. The heteroleptic gallium precursor may include (i) at least one straight chain alkyl group in which a terminal carbon is directly bonded to gallium, and (ii) at least one tertiary alkyl group in which a tertiary carbon is directly bonded to gallium. The method may include reacting the silicon precursor, the germanium precursor, the boron precursor, and the heteroleptic gallium precursor to form a silicon germanium layer on the substrate that is doped with boron and gallium.

Some examples herein provide a method of forming a doped silicon germanium layer. The method may include simultaneously exposing a substrate to (a) a silicon precursor, (b), a germanium precursor, (c) a boron precursor, and (d) a heteroleptic gallium precursor. The heteroleptic gallium precursor may include (i) at least one straight chain alkyl group in which a terminal carbon is directly bonded to gallium, and (ii) at least one tertiary alkyl group in which a tertiary carbon is directly bonded to gallium. The method may include reacting the silicon precursor, the germanium precursor, the boron precursor, and the heteroleptic gallium precursor to form a silicon germanium layer on the substrate that is doped with boron and gallium.

Disclosed herein are compositions and methods for making polycrystalline thin films having very large grains sizes and exhibiting improved properties over existing thin films.

Disclosed herein are compositions and methods for making polycrystalline thin films having very large grains sizes and exhibiting improved properties over existing thin films.

A method for manufacturing a carbon-doped silicon single crystal wafer, including steps of: preparing a silicon single crystal wafer not doped with carbon; performing a first RTA treatment on the silicon single crystal wafer in an atmosphere containing compound gas; performing a second RTA treatment at a higher temperature than the first RTA treatment; cooling the silicon single crystal wafer after the second RTA treatment; and performing a third RTA treatment. The crystal wafer is modified to a carbon-doped silicon single crystal wafer, sequentially from a surface thereof: a 3C-SiC single crystal layer; a carbon precipitation layer; a diffusion layer of interstitial carbon and silicon; and a diffusion layer of vacancy and carbon. A carbon-doped silicon single crystal wafer having a surface layer with high carbon concentration and uniform carbon concentration distribution to enable wafer strength enhancement; and a method for manufacturing the carbon-doped silicon single crystal wafer.

There is a method for forming an oxide or chalcogenide 2D semiconductor. The method includes a step of growing on a substrate, by a deposition method, a precursor epitaxy oxide or chalcogenide film; and a step of sulfurizing the precursor epitaxy oxide or chalcogenide film, by replacing the oxygen atoms with sulfur atoms, to obtain the oxide or chalcogenide 2D semiconductor. The oxide or chalcogenide 2D semiconductor has an epitaxy structure inherent from the precursor epitaxy oxide or chalcogenide film.

There is a method for forming an oxide or chalcogenide 2D semiconductor. The method includes a step of growing on a substrate, by a deposition method, a precursor epitaxy oxide or chalcogenide film; and a step of sulfurizing the precursor epitaxy oxide or chalcogenide film, by replacing the oxygen atoms with sulfur atoms, to obtain the oxide or chalcogenide 2D semiconductor. The oxide or chalcogenide 2D semiconductor has an epitaxy structure inherent from the precursor epitaxy oxide or chalcogenide film.

A solar cell includes a light-receiving surface electrode formed on a light-receiving surface, a back surface electrode formed on a backside, and a CZ silicon single crystal substrate doped with gallium. The CZ silicon single crystal substrate contains 12 ppm or more oxygen atoms. A spiral oxygen-induced defect is not observed in an EL (electroluminescence) image of the solar cell.