Photovoltaic and dye-sensitized solar cells

Photovoltaic Solar Cells

Photovoltaic solar cells convert sunlight directly into electricity by the photovoltaic effect.
They’re made from semi-conductor material such as silicon which is doped to create a P-N junction.
When photons from sunlight hit the cell, they can provide enough energy to dislodge the electrons.
This results in an electric current as electrons move from n-type (electron rich area) to p-type (electron deficient area) silicon.
A typical solar cell provides a voltage of about 0.5-0.6V, so multiple cells can be connected together in panels to provide a practical level of power.
The major drawback is the initial cost of the panels and the energy to manufacture them, in addition to the fact that they rely on sunlight, which is not always available.

Dye-Sensitized Solar Cells

Dye-sensitized solar cells (DSSC) are a type of thin film solar cell, designed to mimic the photosynthesis mechanism in plants.
In these cells, a porous layer of titanium dioxide nanoparticles, coated with a photosensitive dye, is used to absorb sunlight.
When photons are absorbed, electrons are excited from the ground state into the excited state of the dye, from where they can jump into the conduction band of the titanium dioxide.
This generated electric circuit can be used for electricity production.
Dye-sensitized cells are cheaper and easier to produce than traditional photovoltaic cells, but currently, they’re not as efficient.
Research and development is ongoing with the hope of improving their efficiency and making them a more economically viable option.

Photovoltaic vs. Dye-Sensitized Solar Cells

Both types of cells aim to convert solar energy into electricity but through different mechanisms.
Photovoltaic cells directly convert light into electricity using the photoelectric effect, while DSSCs replicate photosynthesis to generate an electric current.
Photovoltaic cells generally have higher efficiency, but they’re more expensive and harder to manufacture.
Dye-sensitized cells are cheaper and easier to handle, offering potential for wider usage if their efficiency can be improved.