Solar cell and method for producing solar cell
AssigneePanasonic Intellectual Property Management Co., Lt D.
InventorsKenta Matsuyama, Kazunori Fujita, Satoru Shimada
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Abstract
A solar cell according to one embodiment of the present invention is provided with: an n-type crystalline silicon wafer having an n+ layer in the entire wafer surface and in the vicinity thereof, said n+ layer having a higher n-type dopant concentration than the other regions; a low concentration P-containing silicon oxide layer which is formed on a light receiving surface of the n-type crystalline silicon wafer; an n-type crystalline silicon layer which is formed on the low concentration P-containing silicon oxide layer; and a p-type amorphous silicon layer which is formed on the back surface side of the n-type crystalline silicon wafer.
Claims10
A solar cell comprising:
- in an entire wafer surface and a vicinity of the entire wafer surface, an n-type crystalline silicon wafer having an n+ layer having a higher concentration of an n-type dopant than other regions;
- a silicon oxide layer formed on a light receiving surface of the n-type crystalline silicon wafer;
- an n-type crystalline silicon layer formed on the silicon oxide layer;
- and
- a p-type amorphous silicon layer formed on a rear surface side of the n-type crystalline silicon wafer,
- wherein the silicon oxide layer contains an n-type dopant, and
- a concentration of the n-type dopant in the silicon oxide layer is lower than a concentration of n-type dopants in the n+ layer and the n-type crystalline silicon layer.
A method for producing a solar cell, comprising:
- a first step of submerging an n-type crystalline silicon wafer in an acid aqueous solution containing an n-type dopant, and forming a high concentration n-type dopant-containing silicon oxide layer on an entire surface of the wafer;
- a second step of forming an i-type silicon layer with substantially intrinsic amorphous silicon or a substantially intrinsic polycrystalline silicon layer, as a main component, in a region located on one principal surface of the n-type crystalline silicon wafer, of the high concentration n-type dopant-containing silicon oxide layer;
- a third step of thermally treating the n-type crystalline silicon wafer, diffusing the n-type dopant to the n-type crystalline silicon wafer and the i-type silicon layer from the high concentration n-type dopant-containing silicon oxide layer, forming, in the entire wafer surface and a vicinity of the entire wafer surface, an n+ layer having a higher concentration of the n-type dopant than other regions, and forming an n-type crystalline silicon layer by crystallizing the i-type silicon layer;
- a fourth step of removing a part, of a low concentration n-type dopant-containing silicon oxide layer formed by the n-type dopant being partially removed by the third step, that is exposed without being covered with the n-type crystalline silicon layer;
- and
- a fifth step of forming a p-type amorphous silicon layer on the other principal surface side of the n-type crystalline silicon wafer.
Dependencies are inferred from the claim text.