Solar cell having interdigitated contacts and internal bypass diodes

• US 4,933,022 A
• Filed: 11/14/1988
• Issued: 06/12/1990
• Est. Priority Date: 11/14/1988
• Status: Expired due to Fees

• Current Assignee: Electric Power Research Institute, Board of Trustees of the Leland Stanford Junior University (Stanford University)
• Original Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford University)
• Inventors: Swanson, Richard M.
• Primary Examiner(s): Weisstuch, Aaron
• Application Number:
  US07/272,105
• Time in Patent Office: 575 Days
• Field of Search: 136/255, 136/256, 136/244, 136/249 MS
• US Class Current: 136/249
• CPC Class Codes: H01L 27/142 Energy conversion devices photovoltaic modules or arrays of single photovoltaic cells comprising bypass diodes integrated or directly associated with the devices H01L31/0443; photovoltaic modules composed of a plurality of thin film solar cells deposited on the same substrate H01L31/046
• CPC Class Codes: H01L 31/03529 Shape of the potential jump barrier or surface barrier
• CPC Class Codes: H01L 31/0475 PV cell arrays made by cells in a planar, e.g. repetitive, configuration on a single semiconductor substrate; PV cell microarrays PV modules composed of a plurality of thin film solar cells deposited on the same substrate H01L31/046
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy

Abstract

A solar cell structure having dual metal layer contacts or interdigitated metal contact fingers on one surface is provided with internal bypass diodes in each cell. Each bypass diode comprises doped regions in contact with the metal spaced from the doped regions of the active solar cell. The doped regions of the bypass diodes are of opposite conductivity type from the doped regions of the active solar cell for each contact. The bypass diode is spaced from the active region and is shaded from irradiation during normal operation.

Claims

1. A solar cell structure comprising

a substrate of silicone, and

a plurality of cells T formed in one surface of said substrate, each cell having alternate rows of p-type and n-type regions formed in said one surface, a first metal contact structure contacting all p-type regions and a second metal contact structure contacting all n-type regions, said first and second metal contact structures serially connecting a cell with adjacent cells, and a bypass diode formed in each cell each bypass diode comprising an n-type region contacting said first metal contact and a p-type region contacting said second metal contact, said bypass diodes being located in areas of cells not irradiated during normal operation of the cell.

2. The solar cell structure as defined by claim 1 wherein said first and second metal contact structures each contact opposite conductivity-type regions in adjacent cells.

3. In solar cell structure having a plurality of metal contacts with at least a first metal contact contacting doped regions of a first conductivity type in an active portion of the cell and at least a second metal contact contacting doped regions of opposite conductivity type in said active portion of the cell, a bypass diode comprising at least one doped region of first conductivity type in electrical contact with said second meal contact and at least one doped region of said opposite conductivity type contacting said first meal contact, said first and second metal contacts being interdigitated, and said bypass diode being spaced from the doped regions of the active cell.