The Physics of Photovoltaic (PV) Cells

Can't really think of a good physics concept to write about, but this rainy Sunday morning, while I was in my brother's room, I spied the solar panels that my neighbor installed on their roof from my brother's room window, so I immediately took a picture to write about it in a blog. So, here it is:

In each individual PV cells, a semiconductor component absorbs sunlight and covert energy into electricity through the photovoltaic effect. A PV cells is a good example of a p-n junction in which an n-type material is diffused into the surface of a p-substrate. When an n-type and p-type material are together, electrons spontaneously diffuse (n to p) and hole spontaneously diffuse (p to n). As photons from sunlight strike the cells, a mobile electron/hole pair is formed in which an electron moves into the n-region and the hole moves to the p-region. When a photon strikes a valence electron in the semiconductor in the solar cells, energy is increased, which promotes it to a higher band. Therefore, as photons cause electron-hole pairs, current flows to form electricity. In a home, solar cells are established in a circuit powering a home, there is a flow of negatively charged electrons out of the n-material into the circuit and a flow of positively charged holes out of the p-material into the circuit.