Solar panels absorb sunlight and convert it into electricity. In the last couple of years, they have even become synonymous with the term clean energy. Proud homeowners wishing to cut down on their electric bill or reduce their carbon footprint will have these contraptions installed on their roofs. They’re more commonly found in calculators, which removes the need to replace a battery ever so often. But how exactly do these technological marvels work?
Well, each solar panel is made up of smaller components called photovoltaic cells. Each photovoltaic cell is composed of the semiconductor silicon and is divided into an upper and lower layer. When particles of light called photons strike these cells they transfer their energy to the electrons of silicon. The energy transfer allows electrons to escape silicon atoms, but these electrons must be forced to flow in the same direction to create an electric current. This is where the two layers of the photovoltaic cell come into play.
Prior to being assembled the photovoltaic cells undergo a process called doping. Phosphorous is added to the top layer of silicon, which adds electrons to that layer giving it a negative charge. But to the bottom layer boron is added, which steals electrons from the silicon particles giving them a positive charge.
Where these two opposite charges meet an electric field is created. This imbalance is maintained because silicon is a semiconductor, but more importantly, this electric field forces the electrons to flow in the same direction as a current. This current is then drawn away to be stored or used. And that’s basically how solar panels work.