Monocrystalline solar cells
Monocrystalline solar cells

Types of solar cells - efficiency photovoltaic cells

 

There are three types of solar cells commonly used. Mono- and polycrystalline silicon solar cells as well as thin-film cells. The efficiency of the photovoltaic cell is dependend on the cell structure. 

 

    • monocrystalline solar cells
    • polycrystalline solar cells
    • thin-film cells

 

Monocrystalline solar cells

Monocrystalline solar cells are manufactured from round single crystals (ingots) having a diameter of 20 - 40 cm and a length of up to 4m. Mainly according to the Czochralski method. By chamfering and cutting the single crystals smaller units are obtained. These units / blocks are wire-sawed into 300µm thick wafers.

The efficiency of monocrystalline lays between 14% and 18%.

 

Polycrystalline solar cells

Polycrystalline solar cells are manufactured from silicon blocks (40cm x 40cm x 30cm). Crystals with different grain orientations can clearly be identified as larger fragments, giving the photovoltaic cell its distinct look.

The blocks are first processed to cuboids and then to wafers with a thickness of around 300µm.

The efficiency of monocrystalline lays between 12% and 16%.

 

Thin-film cells (thin-film solar cells)

A thin film of photoactive semiconductor material is vapor coated onto a carrier material. This is done at temperatures of < 250°C. Glass, plastic and metal serve as carrier material. The most popular photoactive material for thin-film cells is amorphous silicon.

Other materials in use gallium arsenide (GaAs), cadmium telluride (CdTe) and copper-indium-(gallium)-sulfur-selenium the so-called CI(G)S cells.

The efficiency of these solar cells ranges between 6% and 8% (CIS cells up to 12%). In the laboratory, efficiencies of up to 20% were reached for CIS cells.