Perovskite solar cells

Studies within the solar industry have been made about the big P word; perovskite. Solar researchers overtime have requested large amounts of funding for perovskite projects that may provide a break through in the way of solar. So what’s all the solar hype about? Let’s first dive into what perovskite is. Perovskites is a category of materials that display attractive properties like magnetoresistance and superconductivity, just to name a few. These synthesized materials are viewed as the next generation of solar cells.

It enables economical and effective photovoltaics. Solar experts believe that perovskite will play a pivotal role in sensors, lasers, and batteries. A perovskite solar cell is a form of solar cell that includes a perovskite compound. This flexible and light-weight compound has a layer that actively harvests light. It holds intrinsic traits such as  fast charge separation, broad absorbtion, long carrier separation lifetime and more. It’s said to be a cost efficient to product and manufacture. There’s a strong possibility it holds promise for higher efficiencies all around. 

The solar hype 

The gifts that these materials provide have caused a lot of hype in the solar power industry. Next step talks of commercializing them is on its way. Despite these talks, are their disadvantages? First off, the cells have a short lifespan and decay quickly in the face of moisture. The then decayed solar cells then attack metal electrodes. To prevent decay, extensive encapsulation  maybe needed that increase the cost and weight of the material. Toxicity is a leading concern for perovskite solar cells as well. Pbi is the toxic breakdown product of perovskite that maybe carcinogenic. In addition, these cells apply lead which is a pollutant. Research is currently being conducted to cultivate substitutions. 

Silicon with perovskite has record efficiency of 25.2 percent

After decades of extensive research, silicon-based solar cells have hit their maximum theoretical efficiency. New concepts are required to achieve a long-term decrease in solar electricity costs and permit photovoltaic technology to become a more accepted way of generating power. One solution is to place two different types of solar cells on top of each other to maximize the conversion of light rays into electrical power.

These "double-junction" cells are researched in the scientific community, but are expensive. Now research teams from EPFL's Photovoltaics Laboratory and the CSEM PV-center created an economical answer. The researchers added a perovskite cell on top of a standard silicon-based cell that has a record efficiency of 25.2%. The method is promising because the price is more reasonable to the current silicon-cell production process. 

Second solar chance  

Despite these obstacles, perovskite solar cells are still viewed in a good light for future solar cells. Lengthening shelf life, increasing its stability and productivity, and replacing unsafe materials with safer ones is still in the works. Researches are looking to marry perovskites solar cells with other technologies such as silicon. Tandem cells are made by combining silicon and perovskite cells.

Time will tell if these combinations will work. It is a high risk with potentially high profit at this time. 

Commercializing perovskite solar cells is currently in the works. It’s been discovered that transporting the material decays under the exposure of moisture, air, and heat. If its determined that perovskite solar cells provide solar energy safely and effectively, there’s a strong possibility it will be the new mainstream for businesses and consumers alike.

Solar businesses are chomping at the bit for this new technology of solar cells. Its advantageous to be one of the first companies to new cutting edge solar products. 

On a world view perspective, solar may ultimately be the source of energy for humanity. There maybe no other technology that can compete with solar. Solar in some parts of the world, especially Sun belt regions are already the most economical source of electricity. This concept may significantly reduce the costs of energy based on magnitude. It’ll be a matter of time to determine if perovskite is indeed the rising star of solar energy. 

A nanometric success sandwich

Perovskite's unique properties have prompted research into its use in solar cells. The efficiency of the cells has risen by a factor of six and has a high conversion efficiency at a limited production cost. In tandem cells, perovskite complements silicon. It translates blue and green light more efficiently, while silicon is better at converting red and infra-red light.

"By combining the two materials, we can maximize the use of the solar spectrum and increase the amount of power generated. The calculations and work we have done show that a 30% efficiency should soon be possible," say the study's main authors Florent Sahli and Jérémie Werner. Despite its huge popularity, developing an effective tandem structure by superposing the two materials is difficult. Silicon's surface have several pyramids measuring around 5 microns that traps light and prevent it from being reflected. The surface’s texture makes it an issue to place a film of perovskite. When the perovskite is deposited in liquid form,   it stores  between the pyramids that result in short circuits. 

Scientists have resolved the problem by applying evaporation methods to form an inorganic base, porous layer that covers the pyramids. This enables it to retain the liquid organic solution added using a thin-film deposition method called spin-coating. Its heated to a  temperature of 150°C to crystallize a homogeneous film of perovskite on top of the silicon pyramids. "Until now, the standard approach for making a perovskite/silicon tandem cell was to level off the pyramids of the silicon cell, which decreased its optical properties and therefore its performance, before depositing the perovskite cell on top of it. It also added steps to the manufacturing process," says Florent Sahli.

Disadvantages of perovskite 

With their fame comes talks to commercialize the material for workable solar energy. With these talks, comes with learning their disadvantages. The cells have a brief lifespan and decay faster in the face of moisture. From there, the decayed solar cells then attack metal electrodes. To prevent decay, scalable encapsulation maybe needed to increase the cost and weight of the material. Toxicity is an obtable for perovskite solar cells. Pbi is the toxic breakdown of perovskite that maybe carcinogenic. These cells apply lead that’s pollutant. Research is currently being conducted to cultivate substitutions.