New and Emerging Solar Cell Materials|| Perovskite

 

                        

Imagine creating solar panels without relying on materials on short in supply and adopting an eco-friendlier production process. And at the same time boosting efficiency? Enter Perovskite Tandem Solar Cells—an innovation that has long held the promise of revolutionizing the solar energy landscape. But where are they in their development, and could they truly represent the future of solar panel technology?  #perovskite #solarenergy #tandem solar cells.

It promises improvements to solar cells that are almost too good. The regular solar cells you know are made with silicon. And they are actually quite inefficient at converting sunlight into energy. Only about 20 to 25% of sunlight can be captured on a commercial size. But that silicon needs to be mined. And purified in energy intensive processes that require more than 1,000 degrees Celsius of heat. But a new material called perovskite might actually be able to solve all of this. To understand why they are so superior to standard silicon cell. There has been a lot of research on perovskites as sun absorbing materials for about a decade.

  

Perovskite solar cells are a type of thin-film cell and are named after the eponymous ABX₃ crystal structure, with the most studied PV material being methylammonium (MA+) lead (Pb+2) iodide (I-), or MAPbI3. One of the most common combinations in this structure is methylammonium as the A on the corners, the metal lead for B in the centre and the chloride or iodide as the X which form around the metal. But there is quite a vast range of materials that can be used and combined. Methylammonium chloride and Lead iodide are mixed together to create our ABX3 crystal structure. This happens inside enclosed compartments so that no water or oxygen comes in contact with  precious perovskite. The main advantages of perovskite over silicon as a material is the ease of processing. So, silicon is something that is relatively energy intensive to fabricate, but this is something that can be done at close to room temperature.#  New and Emerging Solar  Cell Materials

It doesn't require much energy, so it's easy to do. Everything is relatively abundant and so it shouldn't be a bottleneck for production. So, these base materials are more abundant than silicon and are easier to process. Now we have the base materials, Perovskite Solar Cell but how do we make a sun absorbing perovskite out of it?

The solution: Perovskite is deposited and then it spins up quite fast, so something like 4,000 revolutions per minute. And then it is dropped on this anti-solvent solution and this drives the crystallization of the perovskite film."

The method is called spin coating. But perovskite solar cells can also be directly printed onto surfaces, using similar processes to those used for printing newspapers.

Another method is evaporating perovskites onto surfaces.

Spin coating usually takes place in a lab environment and it can be tedious.

After the spin coating it goes onto a heating plate and the darkening shows us that the crystals are being formed. It works the same way as when salt water evaporates and you start to see the salt.

There are cells which are only made out of perovskite, but in many cases there's a silicon layer beneath them. These cells are called tandem cells. They are the most promising candidates when it comes to increasing the efficiency of solar cells. But at some point, it might be possible to abandon silicon completely. To test their tandem cells efficiency, the researchers use a sun simulator. It determines exactly how much sunlight is converted into electricity. A tandem solar cell reach that much more efficiency 30%.

Tandem solar cells make much more use of the incoming light. So, we have our solar spectrum and the solar cells, they share the spectrum.

The perovskite solar cell in this case makes use of the visible wavelengths. So, everything that we can see by eye is then converted into perovskite solar cell into electrical energy whereas the infrared light passes through the perovskite cell and is then converted into silicon solar cell

which is quite efficient in converting infrared light. So, they share the spectrum and each cell is very efficient in their region.

Roughly 50% more sunlight can be converted into electrical energy using these tandem cells. Before Perovskites go into serial production, there is a lot of stuff that needs to be fixed.

A major issue is the stability of perovskite structures used in tandem solar cells. Perovskite structures are easily put together at low temperatures, but they also come apart easily.

Even the charges that travel through the perovskite in a solar cell can create defects

and destroy the perovskite structures. Also, external factors like moisture, heat, oxygen

and UV light can break it down further and quickly decrease its record-breaking efficiency.

This whole process is called degradation which researchers and companies are trying to fight

with different forms of encapsulation. It seals off the solar modules from external influences

and is an essential step for commercialization that they're going to last for 25 years."

But tandem solar have another thing coming: Economical Problems “If perovskite is going to go anywhere, it will need to be cheaper than ordinary crystalized silicon on a per watt basis."

According to the International Renewable Energy Agency, since 2010, costs for electricity from solar have declined by 89% globally. It’s now more expensive to install silicon panels than it is to make them. Meaning the limiting factors for solar aren't the manufacturing costs, but grid connection, land permits or labour for installation.

It really comes down to the company that solves the cost and the stability factor

and manages to get these is to stable volume production will make a lot of money.

Looking at today's efficiency numbers, solar parks like that would generate 25% more energy

than comparable silicon solar parks.

 

The graphical representation includes:

1. Pie Chart: Shows the power production distribution of a tandem solar cell by light spectrum:
• Infrared Light: 50%
• Visible Light: 40%
• Ultraviolet Light: 10%
2. X-Y Graph: Displays the normalized efficiency of:
• Silicon Solar Cells (blue line): Peaking at specific wavelengths corresponding to the silicon bandgap.
• Tandem Solar Cells (green line): Capturing a broader spectrum with multiple peaks due to their multi-junction design.

 

Here is a comparison chart between silicon solar cells and tandem solar cells:

Feature	Silicon Solar Cells	Tandem Solar Cells
Structure	Single-junction	Multi-junction (e.g., perovskite-silicon)
Efficiency	Typically 20–26%	Can exceed 30% (under lab conditions)
Material Composition	Crystalline silicon	Combination (e.g., silicon + perovskite)
Energy Bandgap	Single bandgap (~1.1 eV)	Multiple bandgaps for broader spectrum
Cost	Mature and affordable	Currently higher due to complex fabrication
Technology Maturity	Well-established and commercialized	Emerging and under research for scalability
Spectral Coverage	Limited to specific wavelengths	Enhanced with multi-bandgap materials
Stability	Highly stable and durable	Stability depends on material combinations
Temperature Sensitivity	Moderate	Varies; can be optimized with materials used
Fabrication Complexity	Simpler	Complex; requires advanced deposition methods
Applications	Rooftops, utility-scale, consumer use	High-efficiency niche markets, research
Environmental Impact	Lower production toxicity	Varies; some tandem materials are less eco-friendly

Key Differences:

• Efficiency Advantage: Tandem cells outperform silicon cells by capturing a broader spectrum of sunlight.
• Cost and Complexity: Silicon cells are more cost-effective, while tandem cells are still in the optimization phase for mass production.
• Applications: Tandem cells are more promising for high-efficiency markets but need more development to rival silicon's widespread use.

 

 

Here's some information about the economics of perovskite PV cells in India:

• Cost

A perovskite cell currently costs around ₹12-13 per watt, while a polycrystalline silicon solar cell costs around ₹25.5/watt, and a monocrystalline silicon solar cell costs around ₹31/watt. With further advancements, the price of a perovskite cell may decrease to ₹7-8 per watt. 

• Manufacturing

P3C Technology and Solutions Pvt Ltd is India's first and leading perovskite solar cell manufacturing company. 

• Market size

The global perovskite solar cell market size was valued at USD 64.05 million in 2023. It is projected to grow from USD 105.23 million in 2024 to USD 1,760.59 million by 2032. 

• Efficiency

Perovskite-silicon tandem cells have reached efficiencies of almost 34%. However, perovskite PV is not yet manufactured at scale and faces a number of challenges before it can become a competitive commercial PV technology. 

Conclusion:

Solar tandem cells have a great potential, but there are still a lot of things that need to fall into place for them to work. And I'm really curious if they are actually going to be on the market next year already.