The electricity production from solar energy is based on the principle of photovoltaic effect. The photovoltaic effect was first discovered in 1839 by French physicist A. E. Becquerel and the first solar cell was created in 1883 by Charles Frits.

Solar battery, also called solar cell, solar element, photoelectric cell, photoelectric element, photovoltaic converter is a semi-conductor device that converts light energy into electricity. It serves two functions:

  • Generation of carriers (electrons and electronic holes) in the light-absorbing material under the influence of the falling light on it;
  • Separation of carriers (this conversion is called an internal photoelectric effect).

pv elements

The photoelectric elements of the first generation consist of a single-layer silicon p-n diode (LED with P-N transition) with a large area, which in presence of sunlight is able to generate usable electricity.

Тhe photoelectric cells of the second generation are based on multilayer p-n diodes. Each layer is designed to absorb light waves with increasing wavelength (decreasing energy). Therefore to absorb a larger part of the solar spectrum and to increase the amount of the utilized energy.

The photoelectric cells of the third generation do not use the traditional p-n transition. They include layers of organic polymer batteries and solar cells with semiconductor nanocrystals.

The most popular types of solar cells are based on silicon. The first type is known as thick layers - from crystalline silicon and other type is known as thin film – based on amorphous silicon. In fact, thick layer cells can be either monocrystalline or polycrystalline type. Both are made of silicon wafers with high purity and a thickness of 0.4 mm. In mass production, a higher efficiency is obtained from monocrystalline silicon cells. For such a solar cell, under normal conditions:
T = 25 °C and the radiation level G = 1000 W/m²,the efficiency reaches 13 ÷ 16 %, depending on the quality of workmanship, production methods and the silicon purity.

Monocrystalline photovoltaic cell Polycrystalline photovoltaic cell Polycrystalline photovoltaic cell