1.5: Progress in the understanding of solar cells
It took until quantum physics was developed to understand the photovoltaic effect. In 1904, Albert Einstein explained the
photoelectric effect [9], which is closely related to the photovoltaic effect, and later he received the Nobel prize for that.
The first solar cell made of silicon was patented in 1941 by Russel Ohl [10][11][12], and it took until 1954 that
solar cells were improved beyond 1–2% efficiency [13]. This progress was only possible because the involved people had a
good understanding of quantum processes while they were developing the necessary fabrication techniques. This is the same in today's progress.
The following chapter gives you an illustrative access to these parts of quantum physics that you require to understand photovoltaics thoroughly.
Nowadays, about 60% of electric power is still produced from coal* by means of Faraday's induction law, and is contributing substantially
to global warming. If you decide to work in photovoltaics, you can help to make our future a lot better.

Figure 1: Excerpt from Altbert Einstein's publication about the photon [9].

Figure 2: A silicon solar cell sketched in Russel Ohl's patent [10].