Silicon Solar Cell Parameters

Source: ResearchGate

Understanding the Design of Silicon Solar Cells

Substrate Material

Silicon is the dominant material used in solar cell manufacturing due to its abundance and prevalence in the semiconductor industry. Despite not being the ideal material for solar cells, its properties make it challenging for other materials to compete. Silicon’s band gap and absorption coefficient are not optimal for solar cell efficiency, but its abundance and manufacturing infrastructure make it a popular choice.

Cell Thickness

Typically, silicon solar cells are between 200 and 500µm thick, with the optimum thickness being around 100µm. The thickness choice is a balance between practical considerations like wafer handling and surface passivation requirements.

Doping of Base

The level of doping in the base of a silicon solar cell affects its voltage and resistance. Higher doping levels can improve voltage but can also damage the crystal structure.

Reflection Control

The front surface of a silicon solar cell is textured to enhance light absorption, increasing the overall efficiency of the cell.

Emitter Dopant

N-type silicon, with higher surface quality than p-type silicon, is typically used at the front of the cell where light absorption is highest.

Emitter Thickness

By keeping the emitter layer thin, a large portion of the generated carriers are located close to the p-n junction, enhancing efficiency.

Doping Level of Emitter

The front junction is doped to a level that allows efficient conduction of generated electricity without significant resistive losses.

Grid Pattern

A metal grid with low resistivity is placed on the cell’s surface to conduct generated current. The grid’s width and spacing are optimized to balance light collection and electrical resistance.

Rear Contact

While the rear contact is less critical than the front contact, its design becomes increasingly important as solar cell efficiency improves and cells become thinner.

By understanding these key design aspects, researchers and manufacturers can continue to innovate and improve the efficiency of silicon solar cells.

Feel free to comment your thoughts.