Newer Semiconductor Materials.

September 16, 2021 bandgap, cell, cells, DSSC, dye, inorganic, nanoparticles, OPV, organic, perovskite, polymer, PPV, PV, quantum dots, solar, thin-film, titanium dioxide No Comments

Newer Materials.

1. Dye-Sensitized.

Another type of solar cell material is a small molecule dye, such as a ruthenium metalorganic dye, that can absorb a broad range of the visible region of sunlight. An inorganic mesoporous nanoparticle layer, usually titanium dioxide, increases the area for light absorption. Solar cells using these materials can be made using solution processing, making them inexpensive to fabricate.

Dye-sensitized solar cells (DSSCs) belong to the group of thin-film solar cells which have been under extensive research for more than two decades due to their low cost, simple preparation methodology, low toxicity and ease of production.

Still, there is lot of scope for the replacement of current DSSC materials due to their high cost, less abundance, and long-term stability.

2. Organic/Polymer.

Semiconducting polymers such as polyphenylene vinylene (PPV) and small organic small molecules such as phthalocyanines, polyacenes, and squarenes are also used in solar cells. These highly conjugated organic molecules have a broad absorption in the visible and near infrared region. These materials are deposited as thin films either by vacuum deposition methods or solution processing, and solar cells using these materials are usually thin and flexible. However, the efficiency of these cells is still low, just a little more than 10%, hence they have not been commercialized yet.

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.

They can also be applied to a variety of supporting materials, such as flexible plastic, making OPV able to serve a wide variety of uses.

3. Perovskite.

Perovskite cells are generally hybrid organic-inorganic lead or tin-halide materials, such as methylammonium lead halide. The cells are built with layers of materials that are printed, coated, or vacuum-deposited onto an underlying support layer, known as the substrate.

These materials can be solution-processed, hence enable inexpensive and simple fabrication. They are typically easy to assemble and can reach efficiencies similar to crystalline silicon.In the lab, perovskite solar cell efficiencies have improved faster than any other PV material, from 3% in 2009 to over 25% in 2020.

One of the key advantages of these materials is their ability to absorb sunlight across the entire visible spectrum.

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.

4. Quantum dots.

Nanoparticles, a few nm in size, called quantum dots are another type of emerging materials used in solar cells that conduct electricity through tiny particles of different semiconductor materials just a few nanometers wide. They are low bandgap semiconductor materials such as CdS, CdSe, and PbS. Their bandgaps can be tuned over a wide range by changing the size of the particles.

Quantum dots provide a new way to process semiconductor materials, but it is difficult to create an electrical connection between them, so they’re currently not very efficient. However, they are easy to make into solar cells. They can be deposited onto a substrate using a spin-coat method, a spray, or roll-to-roll printers like the ones used to print newspapers.

Many common materials used for fabricating quantum dots such as Cd and Pb are considered toxic, hence other alternative materials such as copper indium selenide are being developed.