{
  "patent_number": "US 2780765",
  "country": "US",
  "title": "How the First Practical Silicon Solar Cell Works",
  "original_title": "Solar energy converting apparatus",
  "summary": "A 1954 invention by Bell Labs researchers that created the first silicon-based solar cell capable of converting sunlight into enough electricity to power everyday devices.",
  "what_it_does": "This patent describes a device that uses a silicon body to turn sunlight into electrical current to charge a battery. It creates a p-n junction by placing a thin p-type zone, doped with boron, next to an n-type zone. The p-type zone is kept thin—specifically, about the same thickness as the distance electrons can travel before recombining—to ensure electricity is generated efficiently. It also includes a one-way electrical gate, known as a unilaterally-conductive element, to ensure power flows from the solar cell to the battery but prevents the battery from draining back through the cell at night.",
  "what_it_does_not_cover": [
    "Does not cover solar cells made from materials other than silicon.",
    "Does not cover solar power systems that lack a battery for energy storage.",
    "Does not cover the use of non-boron impurities for creating the p-type zone.",
    "Does not cover solar cells without the specific one-way electrical gate (diode) for preventing battery discharge."
  ],
  "filed": "1954-03-05",
  "granted": "1957-02-05",
  "expires": "1974-03-05",
  "status": "expired",
  "holder": "Bell Telephone Laboratories Inc",
  "holder_url": "https://patentbrief.org/company/bell-telephone-laboratories-inc",
  "inventors": [
    {
      "name": "Daryl M Chapin",
      "url": "https://patentbrief.org/inventor/daryl-m-chapin"
    },
    {
      "name": "Calvin S Fuller",
      "url": "https://patentbrief.org/inventor/calvin-s-fuller"
    },
    {
      "name": "Gerald L Pearson",
      "url": "https://patentbrief.org/inventor/gerald-l-pearson"
    }
  ],
  "times_cited": 59,
  "tags": [
    "energy",
    "semiconductors",
    "consumer_electronics"
  ],
  "abstract": null,
  "url": "https://patentbrief.org/patent/us/2780765/solar-cell-photovoltaic",
  "markdown_url": "https://patentbrief.org/patent/us/2780765/solar-cell-photovoltaic/md",
  "google_patents_url": "https://patents.google.com/patent/US2780765",
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}