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How do semiconductors contribute to the advancement of renewable energy technologies?

Shaquita Krammer

Semiconductors play a crucial role in the advancement of renewable energy technologies, particularly in the development of solar cells and other photovoltaic devices. In essence, the conversion of solar energy to electricity is made possible by semiconductors.

Semiconductors are materials that have properties that lie between those of conductors and insulators. Unlike conductors, such as copper and aluminum, which allow electricity to easily flow through them, semiconductors have low electrical conductivity. However, they have an electrical resistance that can be controlled through the addition of impurities, or dopants, which give rise to two types of semiconductors: n-type and p-type. The n-type semiconductor has negative charges, or electrons, added to the crystal lattice, while the p-type has positive charges, or holes – places where electrons are missing in the lattice structure.

When n-type and p-type semiconductors come into contact with each other, a shift in electric potential occurs, creating a junction known as a pn junction. Photons from sunlight can then hit the semiconductor material, thus creating electron-hole pairs that can move along the junction and create a flow of electricity.

Silicon has been the dominant material used in solar cells, as it has the necessary bandgap to absorb enough energy from sunlight to free electrons and create electrical current. However, because silicon is relatively expensive and not always abundant, there has been significant interest in developing materials and technologies that can harness sunlight with a greater degree of efficiency and at a lower cost.

These challenges have been addressed through research and development in a host of other semiconductor materials and technologies that can coalesce sunlight and produce electrical current with higher yields, such as cadmium telluride, copper indium gallium selenide, and organic materials, such as polymers. These alternative materials and technologies can address some of the limitations of silicon, such as its relative inflexibility in the shape and size of the modules, and slow radiation resistance, which can reduce overall efficiency.

Moreover, it has been recognized that the integration of energy storage systems with solar cells can enable the efficient capture and storage of solar-generated electricity. A key way that semiconductors make this possible is through the creation of supercapacitors and batteries that can store energy generated by photovoltaic cells. Semiconductors are also used in inverters that convert the direct current generated by the solar cells to the alternating current that is needed to power the electrical grid.

Overall, semiconductors are critical to the advancement of renewable energy technologies, particularly in the development of photovoltaics. The continued research and development of these materials and technologies hold great promise for the widespread adoption of renewable energy sources, which can reduce reliance on fossil fuels and mitigate the harmful impacts of climate change.