How solar cells work
Sunlight shines on the semiconductor p-n junction to form a new hole-electron pair. Under the action of the built-in electric field in the p-n junction, the light-generated holes flow to the p-area, and the photo-generated electrons flow to the n-area, and a current is generated after the circuit is turned on. This is the working principle of photovoltaic effect solar cells. Solar cells, also known as solar chips or photovoltaic cells, are a kind of photoelectric semiconductor sheet that uses sunlight to directly generate electricity. As long as it is exposed to light that meets certain illuminance conditions, it can instantly output voltage and generate current when there is a loop.
The basis of the working principle of solar cells is the photovoltaic effect of the semiconductor PN junction. The so-called photovoltaic effect is when the object is illuminated, the charge distribution state in the object changes to produce an effect of electromotive force and current. When sunlight or other light irradiates the PN junction of the semiconductor, a voltage appears on both sides of the PN junction, which is called photo-generated voltage. There are two ways of solar power generation, one is photothermal-electric conversion, and the other is photoelectric direct conversion.
The difference between solar battery and lithium battery
Most smart electronic products now use rechargeable lithium batteries. Especially for mobile electronic devices, because of its light weight, portability and multiple application functions, users are not restricted by environmental conditions during use and have a long operating time. Therefore, lithium batteries have become the most common choice despite their battery life weakness.
Although solar batteries and lithium batteries sound like the same type of products, they are not always the case. There is still the most essential difference between the two. Simply put, solar cells are a kind of power generation equipment that cannot directly store electrical energy, while lithium batteries are a type of storage battery that can continuously store electricity for users.
The working principle of solar cells (inseparable from sunlight)
Compared with lithium batteries, one disadvantage of solar batteries is revealed, that is, they cannot be separated from the sunlight. The conversion of solar energy into electricity is synchronized with the sunlight in real time. Therefore, for solar energy, it is only during the day or even on sunny days. At home, it cannot be used flexibly as long as the battery is fully charged like a lithium battery.