Solar cell

• US 4,029,518 A
• Filed: 11/20/1975
• Issued: 06/14/1977
• Est. Priority Date: 11/20/1974
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Matsutani, Toshinobu, Nishida, Keiichi
• Primary Examiner(s): Mack, John H.
• Assistant Examiner(s): Weisstuch, Aaron
• Application Number:
  US05/633,978
• Time in Patent Office: 572 Days
• Field of Search: 136/89, 357/20, 357/30, 357/56, 357/65, 357/68, 250/211 J
• US Class Current: 136/256
• CPC Class Codes: H01L 31/068 the potential barriers being only of the PN homojunction type, e.g. bulk silicon PN homojunction solar cells or thin film polycrystalline silicon PN homojunction solar cells
• CPC Class Codes: Y02E 10/547 Monocrystalline silicon PV cells

Abstract

A P-type diffusion layer is formed on an N-type silicon semiconductor wafer to establish a P-N junction in a solar cell, the diffusion layer being exposed to radiation. A pair of electrodes are formed on the surfaces of the diffusion layer and the semiconductor wafer in a desired configuration in order to provide output of electric energy generated by the solar cell. The diffusion layer is formed in such a manner that the layer has a thickness of around 3 μm at areas where the electrode is formed and has a thickness of around or below 0.5 μm at regions on which the electrode is not formed. With such an arrangement, radiation having a wavelength of about or shorter than 400 mμm can be used for performing optoelectric generation.

Claims

1. A solar cell comprising:

a semiconductor wafer of one conductivity type;

a diffusion layer of a conductivity type opposite to the conductivity type of the semiconductive wafer disposed on a first suface of said semiconductive wafer, said diffusion layer being formed on said first surface and having an etched surface providing thinner regions and thicker regions of a desired configuration;

a first electrode formed on a second surface of said semiconductor wafer opposite to said first surface; and

a second electrode formed on said thicker regions of said diffusion layer.

2. The solar cell of claim 1, wherein the semiconductor wafer is an N-type silicon semiconductor wafer and the thin layer is a P-type diffusion layer.

3. The solar cell of claim 1, wherein the thicker regions of the diffusion layer have a thickness of about 3 μ

m and the other portions of the thin layer have a thickness of about 0.5 μ

m.

4. The solar cell of claim 1, wherein the thicker regions are comb-shaped.