Dye-sensitized solar cell

Dye.sensitized.solar.cells

Operating diagram of DSC

Dye Sensitized Solar Cell Scheme

BlackDye

Dye-sensitized solar cell

A dye-sensitized solar cell (DSSC) is a low-cost solar cell belonging to the group of thin-film solar cells. It is based on a semiconductor formed between a photo-sensitized anode and an electrolyte, a photoelectrochemical system. The modern version of a dye solar cell, also known as the Grätzel cell, was originally co-invented by the Swiss chemist Michael Grätzel and Brian O'Regan at the École Polytechnique Fédérale de Lausanne in 1991.

Structure and Operation

Dye-sensitized solar cells are composed of a porous layer of titanium dioxide nanoparticles, covered with a molecular dye that absorbs sunlight, much like the chlorophyll in green leaves. The titanium dioxide is immersed under an electrolyte solution, with a platinum-based catalyst on the counter electrode.

When sunlight strikes the dye, electrons are excited to a higher energy state. These electrons are injected into the conduction band of the titanium dioxide and travel towards the transparent conducting oxide (TCO) layer, creating an electric current. The electrons then flow through an external circuit before returning to the cell via the counter electrode, where they are transferred back to the dye via the electrolyte, completing the circuit.

Advantages

Dye-sensitized solar cells offer several advantages over traditional silicon-based solar cells:

• Lower production costs due to the use of inexpensive materials and simpler manufacturing processes.
• Flexibility in design, allowing for the creation of semi-transparent and flexible solar panels.
• Better performance in low-light conditions and at higher angles of incidence.

Disadvantages

Despite their advantages, DSSCs also have some limitations:

• Lower overall efficiency compared to traditional silicon-based solar cells.
• Long-term stability and durability issues, particularly with the liquid electrolyte, which can lead to leakage and degradation over time.
• Sensitivity to temperature and humidity, which can affect performance and lifespan.

Applications

Dye-sensitized solar cells are used in a variety of applications, including:

• Building-integrated photovoltaics (BIPV), where they can be incorporated into windows, facades, and other architectural elements.
• Portable electronic devices, such as chargers for mobile phones and other small gadgets.
• Off-grid power generation in remote or rural areas.

Future Developments

Research is ongoing to improve the efficiency, stability, and scalability of dye-sensitized solar cells. Some areas of focus include:

• Developing solid-state electrolytes to replace liquid electrolytes, improving stability and longevity.
• Enhancing the light absorption properties of the dye molecules to increase efficiency.
• Exploring new materials and nanostructures for the semiconductor and counter electrode to optimize performance.

Related Pages

• Solar cell
• Thin-film solar cell
• Photovoltaics
• Michael Grätzel
• Titanium dioxide
• Building-integrated photovoltaics

See Also

• Perovskite solar cell
• Organic solar cell
• Quantum dot solar cell

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