Bell Labs Silicon Solar Cell (1954)
April 1954What Happened
Scientists Calvin Fuller, Daryl Chapin, and Gerald Pearson at Bell Telephone Laboratories demonstrated the first practical silicon solar cell, converting 6% of sunlight to electricity. Previous selenium cells managed less than 1%. Bell announced the invention on April 25, 1954, calling it a possible source of unlimited power from the sun.
Outcome
The technology was too expensive for consumer use, costing about $300 per watt. Early applications focused on spacecraft, where cost mattered less than weight and reliability.
Silicon photovoltaics became the dominant solar technology. By 2025, costs had dropped to around $0.20 per watt and efficiency approached the theoretical limit, driving the search for tandem architectures.
Why It's Relevant Today
The 6% efficiency of 1954 established the baseline that tandem cells have now multiplied nearly sixfold. Each efficiency breakthrough compounds the economic case for solar power.
