Solar cells are older than we perhaps knew, and their efficiency was low in their early development. They were also remarkably expensive. Today, though, materials like perovskite are making new, less-expensive and reasonably efficient cells possible. Swapping copper for the more expensive silver conductors may help make these cells even more rewarding. In a further development, a simple plastic film wrap may make perovskite cells safer. A Long History of Low Efficiency Two dates stand out in Wikipedia’s recounting of solar cell development: 1839 –Edmond Becquerel observes the photovoltaic effect via an electrode in a conductive solution exposed to light. 1883 – Charles Fritts develops a solar cell using selenium on a thin layer of gold to form a device giving less than 1-percent efficiency. Only one Watt would be generated for every kilowatt falling on a one-meter square solar panel. Notice the use of gold helping keep the price of these early cells high. Considering that modern solar cells …
