I. Discovery of the Photovoltaic Effect (19th Century)

In 1839, French scientist Alexandre-Edmond Becquerel observed that light striking metal electrodes generates an electric potential—a phenomenon later termed the "photovoltaic effect"—laying the foundational principle for solar energy conversion.

II. Theoretical Conceptions and Early Technological Exploration (1930s–1940s)

• 1930: German physicist Heinrich Lange (Lang Ge) first proposed harnessing the photovoltaic effect to create solar cells, envisioning its practical application in converting sunlight to electricity.
• 1932: Scientists André Auburt and Pierre Stora successfully developed the world’s first cadmium sulfide (CdS) solar cell, marking the earliest experimental realization of photovoltaic technology.
• 1941: American researcher Russell Ohl discovered the photovoltaic effect in silicon—an iconic semiconductor material—unlocking pivotal insights that propelled the field of semiconductor physics and solar cell research.

III. Practical Breakthroughs (1950s)

• 1954: A landmark achievement at Bell Laboratories in the U.S.:
  • Engineers developed the first commercially viable monocrystalline silicon solar cell with 6% energy conversion efficiency, officially inaugurating the era of practical solar power generation.
  • Scientist Harald Wick identified the photovoltaic property in nickel arsenide (NiAs), leading to the creation of the first thin-film solar cell—a precursor to lightweight, flexible solar technologies.

IV. Large-Scale Deployment and Industrial Maturity (Late 20th Century to Present)

• Post-1970s: Driven by global energy crises, photovoltaic technology underwent rapid innovation:
  • Efficiency of crystalline silicon cells surged to 13%–15%, while manufacturing advancements drastically reduced costs, paving the way for commercial scalability.
• 21st Century:
  • By 2023, China’s cumulative installed photovoltaic capacity reached 609 million kilowatts—a tenfold increase over the previous decade—solidifying its role as a global leader in solar energy adoption and production.