Why semiconductors are used in solar cells

Diversity in Chemistry Awards Find awards and scholarships advancing diversity in the chemical sciences. Funding to support the advancement of the chemical sciences through research projects. ACS-Hach Programs Learn about financial support for future and current high school chemistry teachers. A solar cell is made of two types of semiconductors, called p-type and n-type silicon. The p-type silicon is produced by adding atoms—such as boron or gallium—that have one less electron in their outer energy level than does silicon.

The n-type silicon is made by including atoms that have one more electron in their outer level than does silicon, such as phosphorus. Phosphorus has five electrons in its outer energy level, not four. It bonds with its silicon neighbor atoms, but one electron is not involved in bonding.

Instead, it is free to move inside the silicon structure. A solar cell consists of a layer of p-type silicon placed next to a layer of n-type silicon Fig.

In the n-type layer, there is an excess of electrons, and in the p-type layer, there is an excess of positively charged holes which are vacancies due to the lack of valence electrons. Setting your setup on the top of your home would be a standout amongst the most well known decisions. Different alternatives incorporate territories of your yard that don't right now fill a need.

Great article Lot's of information to Read Great Man Keep Posting and update to People.. Thanks Zonnepanelen kopen. Hi there! Nice stuff, do keep me posted when you post again something like this! The measure of power required, alongside the size of the battery, will decide the quantity of hours vitality will last during times of no daylight.

Solar energy refunds are likewise offered by over half of US states. Why semiconductors are used in solar cells not conductors. Then I thought there must be some reason behind this and I started hunting for few books on semiconductors in my library and did a few internet search and alas I found the answer! In photo electric effect the photons strike the element surface and the energy of the photons is transferred to the electrons present in the valence band of the element.

This energy is sufficient to excite the electrons from valence band to conduction band, thus giving rise to free electrons.

These free electrons form the base for the electric current in the circuit. The element on which the photons strike can be a conductor, semiconductor or insulator. Taking the case of insulator, the energy band gap between the valence band and conduction band is very large which means a large amount of energy is needed to eject out the electrons.

Generally the photons from the sunlight do not possess this amount of energy. Photons of high frequency like X-rays may be able to perform this task. This lattice provides an organized structure that makes conversion of light into electricity more efficient.

Solar cells made out of silicon currently provide a combination of high efficiency, low cost, and long lifetime. A thin-film solar cell is made by depositing one or more thin layers of PV material on a supporting material such as glass, plastic, or metal. Both materials can be deposited directly onto either the front or back of the module surface. CdTe is the second-most common PV material after silicon, and CdTe cells can be made using low-cost manufacturing processes.

While this makes them a cost-effective alternative, their efficiencies still aren't quite as high as silicon. CIGS cells have optimal properties for a PV material and high efficiencies in the lab, but the complexity involved in combining four elements makes the transition from lab to manufacturing more challenging. Perovskite solar cells are a type of thin-film cell and are named after their characteristic crystal structure.

Perovskite cells are built with layers of materials that are printed, coated, or vacuum-deposited onto an underlying support layer, known as the substrate. They are typically easy to assemble and can reach efficiencies similar to crystalline silicon. To be commercially viable, perovskite PV cells have to become stable enough to survive 20 years outdoors, so researchers are working on making them more durable and developing large-scale, low-cost manufacturing techniques.

Organic PV , or OPV, cells are composed of carbon-rich organic compounds and can be tailored to enhance a specific function of the PV cell, such as bandgap, transparency, or color. OPV cells are currently only about half as efficient as crystalline silicon cells and have shorter operating lifetimes, but could be less expensive to manufacture in high volumes.