History of electrochemistry
In 1789, Franz Aepinus developed a device with the properties of a "condenser" (now known as a capacitor.) The Aepinus condenser was the first capacitor developed after the Leyden jar, and was used to demonstrate conduction and induction. The device was constructed so that the space between two plates could be adjusted, and the glass dielectric separating the two plates could be removed or replaced with other materials.
Les Hoffman
The invention of the transistor in 1948 must have had an effect on Leslie Hoffman. In the early 1950s, he took a major interest in solar cells, also called photovoltaic cells. When Bell Labs introduced the solar cell to the world in 1951 it was only a curiosity. It had a very poor light-to-electricity conversion efficiency of 2 percent, and was very fragile and expensive to fabricate. Several manufacturers, including Hoffman, managed to improve the efficiency to 4.5 percent by 1954, but photovoltaic cells were still impractical.
Hoffman made great strides in making the solar cell a practical and useful source of renewable energy. From 1957 to 1960, he improved its efficiency from 4.5 to 14 percent and lowered the production cost to make it a marketable item. One of Hoffman's great achievements was the first satellite to be powered by solar cells, the Vanguard 1, launched in 1958. The solar arrays or panels are Hoffman photovoltaic cells. In 1959 H. Leslie Hoffman received the David Packard Medal of Achievement for innovation. In 1959 he was one of the board of directors for the Electronic Industries Association (EIA).