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.

[Problem] To provide a crystal laminate structure having a -Ga.sub.2O.sub.3 based single crystal film in which a dopant is included throughout the crystal and the concentration of the dopant can be set across a broad range. [Solution] In one embodiment of the present invention, provided is a crystal laminate structure 1 which includes: a Ga.sub.2O.sub.3 based substrate 10; and a -Ga.sub.2O.sub.3 based single crystal film 12 formed by epitaxial crystal growth on a primary face 11 of the Ga.sub.2O.sub.3 based substrate 10 and including Cl and a dopant doped in parallel with the crystal growth at a concentration of 110.sup.13 to 5.010.sup.20 atoms/cm.sup.3.

A crystal laminate structure includes a Ga.sub.2O.sub.3-based substrate, and a -Ga.sub.2O.sub.3-based single crystal film formed by epitaxial crystal growth on a principal surface of the Ga.sub.2O.sub.3-based substrate. The -Ga.sub.2O.sub.3-based single crystal film includes Cl and a dopant doped in parallel with the crystal growth at a concentration of not less than 110.sup.13 atoms/cm.sup.3 and not more than 5.010.sup.20 atoms/cm.sup.3.

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.

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 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.

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.

A method of forming a Si-comprising epitaxial layer selectively on a substrate and a semiconductor processing apparatus is disclosed. Embodiments of the presently described method of forming the Si-comprising epitaxial layer comprise performing a deposition process for forming the Si-comprising epitaxial layer selectively on a first exposed single crystalline surface relative to a second exposed single crystalline surface being different than the first exposed single crystalline surface.

A method of forming a Si-comprising epitaxial layer selectively on a substrate and a semiconductor processing apparatus is disclosed. Embodiments of the presently described method of forming the Si-comprising epitaxial layer comprise performing a deposition process for forming the Si-comprising epitaxial layer selectively on a first exposed single crystalline surface relative to a second exposed single crystalline surface being different than the first exposed single crystalline surface.

A composition comprising an engineered defect concentration comprises a metal oxide single crystal having a polar surface and a bulk concentration of interstitial oxygen (O.sub.i) of at least about 10.sup.14 atoms/cm.sup.3. The polar surface comprises a concentration of impurity species of about 5% or less of a monolayer. A method of engineering a defect concentration in a single crystal comprises exposing a metal oxide single crystal having a polar surface to molecular oxygen at a temperature of about 850 C. or less, and injecting atomic oxygen into the single crystal at an effective diffusion rate D.sub.eff of at least about 10.sup.16 cm.sup.2/s.