1.4: The first solar cells*
Soon after, in 1883, the first solar cell panel was made by the New Yorker inventor Charles Fritts . He coated selenium with an
extremely thin layer of gold, so it was transparent to light, and obtained an energy conversion efficiency between 1 and 2%.
Because the photovoltaic effect could not be understood, Fritts contacted a famous expert, Werner von Siemens, who reproduced the
effect and confirmed it .
These pioneers and their contemporaries had no deeper understanding of this effect and were—accordingly—unable to develop
solar cells further. In contrast, the effect of electromagnetic induction was discovered in 1831 by Michael Faraday and was well understood.
This lead to the rapid development of electric generators run on coal-fired steam or water force—and became the means to produce electric
power on a large scale.
Figure 1: Excerpt from Charles Fritts' publication . At his time, the rectifying action of the junction could not be explained.
Figure 2: Another excerpt from Charles Fritts' publication  reporting on stability problems...
Figure 3: ... and on his assembly of cells into a module.
Figure 4: Werner von Siemens' conclusion in his response article to Charles Fritts' publication .