Solar (photovoltaic/PV) energy has been slowly becoming an everyday sight in many countries in the form of PV modules, commonly known as solar panels. This does not mean, however, that the technology is perfected, and there are many exciting developments happening in the industry to be aware of. A particularly fascinating type of PV energy that is experiencing explosive growth in 2025 is Perovskite, which, despite its underdog status, is sure to become a true competitor to silicon in the years to come. Never heard of it? Not even sure how to pronounce it? Not to worry! On this topic, I have had the pleasure of interviewing Dr. Hashini Perera, from the University of Surrey, whose research focuses on increasing the stability and durability of perovskite solar cells. Together, we will learn all about perovskite and Dr. Perera’s impressive work to make them a more viable option going forward.
New to solar energy? Scroll down to find definitions in my English-Spanish glossary of commonly used PV terminology. Alternatively, for a more holistic understanding, why not check out The Interactive Guide to Solar Energy created by Alejandro Giacomelli in Spanish, for which my English translation will soon be live: https://panelesfotovoltaicos.netlify.app/
This will be a longer post, which will be divided into 3 sections: 1) An Introduction to Perovskite, 2) Limitations of Perovskite technology and Dr. Perera’s research, and 3) Future trends. For each section, I will first present a part of my interview with Dr. Perera, and then offer additional information on the topics mentioned. But first, a crash course on solar energy for those of us who don’t have PhDs in electronic engineering!
Solar energy is a renewable, green energy harnessed from light and heat emitted by the sun. It can be used for heating/cooling (a.k.a solar thermal energy), and to generate electricity (a.k.a Photovoltaic energy, or PV), which is the focus of this blog. PV energy is created through the photovoltaic effect, discovered in 1839 by Edmond Bequerel, using PV cells. These are usually made with silicon, and are joined to create PV modules, commonly known as solar panels. It is one of the most popular alternatives to fossil fuels globally. Photovoltaics work by converting sunlight directly into electricity using semiconductor materials. When light hits a solar cell, photons (light particles) transfer their energy to electrons in the material, usually silicon or, as we will learn today, perovskite. The energy knocks electrons loose, creating an electric current. The cell directs these electrons into an external circuit, generating direct current (DC) electricity. This power can then be used directly, stored in batteries, or converted into alternating current (AC) for use in homes, businesses, or on the wider electricity grid. This last use is the one most commonly found in home PV systems. Multiple cells form a solar panel, or “module”, and panels can be connected into larger solar “arrays” for higher energy output.
1) An Introduction to Perovskite
Georgia:
Thank you for your time and congratulations on your graduation and recent publication! I was wondering if you could start by just giving a quick introduction to Perovskite: how is it different from “normal” solar panels? What makes it so exciting for you?
Dr. Perera:
Great question to start with!
So, the regular solar panels you see on rooftops use silicon as the material that absorbs sunlight and turns it into electricity. Perovskites are an exciting alternative to silicon – they’re much cheaper and can be processed more easily, even in a lab or factory setup. You can even print them like you would a newspaper, which opens up a lot of new possibilities for how and where solar panels can be used.
One of the coolest things about perovskites is that we can tune their bandgap – basically, we can adjust which parts of the sunlight spectrum they absorb. This is really important when designing tandem solar cells, where you stack multiple layers, each capturing different parts of the sunlight. By tailoring perovskites in this way, we can make solar cells that use sunlight more efficiently, leading to higher overall performance.
What makes perovskites so exciting for me is how much potential they have to completely change the solar industry. I love how fast the field is moving; perovskite efficiencies have gone from almost nothing to rivaling silicon in just over a decade. It feels like we’re watching the early stages of something big, and being part of that research is super motivating.
As Dr. Perera explains, the solar panels we are used to seeing use silicon as the absorption material (known as “semiconductor material”). In perovskite cells, however, the most common semiconductors are metal-halide compounds such as methylammonium lead iodide (CH₃NH₃PbI₃). These layers are excellent at absorbing sunlight, but are also extremely thin (known as thin-film PV) , which is one of the factors influencing their easier and cheaper manufacture.
Efficiency is one of the biggest factors when designing solar cells, and Perovskite tests have been exceptionally exciting for the high efficiency potential discovered in tandem cells. These are solar cells that use layers to absorb different parts of the solar spectrum. Perovskites are particularly suited to this configuration, because, as Dr. Perera mentions, their bandgaps can be tuned to absorb different parts of the spectrum and there are therefore several possible arrangements. Tandem technologies include “All-Perovskite” cells, or cells that combine perovskite and silicon layers. These cells achieve efficiencies far above what is seen in typical silicon-based panels, for example all-perovskite cells were recently reported as over 29% efficient (Liu, et al., 2025) and in April, LONGi broke the world record for crystalline silicon-perovskite tandem solar cell efficiency at nearly 35% (LONGi, 2025).
So, given these stats and Dr. Perera’s clear excitement about the potential of the technology, you may be wondering why it is still so niche. That is because perovskite still has some serious problems to overcome before it can be commercially viable, one of them being the extremely short lifespan of the cells. This is where work like that of Dr. Perera comes in- to try to eliminate these obstacles. In her case, specifically iodine leakage and cell instability, but I’ll let her explain:
2) Limitations of Perovskite technology and Dr. Perera’s research
Georgia:
That’s amazing! These really are such exciting prospects and the fast development of the tech is incredible- but I’ve heard that Perovskites have some major drawbacks currently impeding their adoption. Your research focuses on the lifespan of these panels and Iodine leakage, and you have made some impressive advancements but many of us don’t know about these yet. So, the floor is yours: tell us about your research! Why do PSCs break down so quickly, and how are you trying to prolong their lifespan? What was your breakthrough? How can alumina nanoparticles help make PSCs last longer?
Dr. Perera:
There are several reasons behind the instability of perovskites. Unlike silicon, which is a stable crystalline material, perovskites are ionic in nature, which gives them some inherent stability issues. These problems are exacerbated by environmental factors like moisture, heat, light, and oxygen. For a material to be used as the light absorber in a solar cell, it needs to be stable against all these conditions, especially since it will be exposed to them during outdoor operation.
In my work, I’ve specifically focused on improving the stability of perovskite solar cells through iodine scavenging. Iodine is a byproduct of perovskite degradation – but it’s not just its formation that causes trouble. The real issue is what happens when iodine leaks into the perovskite crystal structure. This can trigger chain reactions that accelerate perovskite degradation, ultimately reducing the performance and lifetime of the solar cell. And because iodine is highly volatile, this leakage happens quite easily.
In the study published in EES Solar, I showed that we can mitigate this problem by incorporating alumina nanoparticles at the interface between the perovskite and the underlying charge transport layer. These nanoparticles act as iodine scavengers, capturing the iodine before it can enter the perovskite structure. This modification improved the device lifetime by more than 10 times, compared to a commonly used interfacial layer called PFN-Br. This is particularly significant because the charge transport material used here, Me-4PACz, is a key material in tandem solar cells. If you look at record-efficiency tandem devices, you’ll see Me-4PACz used in many of them.
In the study published in EES, I focused on another widely used charge transport material: PEDOT:PSS. This material is especially important for lead-tin perovskites, which are a promising class of perovskites for replacing silicon because they absorb the same part of the solar spectrum that silicon absorbs. In this study, we used a different iodine scavenging material (called BHC) and not alumina nanoparticles.
The perovskite community has long struggled to understand why PEDOT:PSS-based devices perform poorly and degrade faster compared to others. In this collaborative work with researchers from across the globe, we were able to unravel the exact chemical mechanisms behind these losses and further, show how we can can significantly improve both the performance and stability of these devices by using an iodine scavenger.
That was a lot, so let’s break it down further. Perovskite cells are quite unstable and break down very quickly when exposed to the elements. Traditionally, they would degrade in a matter of hours or days, in part due to the creation of iodine, which is extremely damaging to the cell. Dr. Perera’s work focuses on capturing these iodine particles before they can cause further damage (called iodine scavenging), which slows down degradation and allows for longer lasting cells. In the EES Solar study using alumina ( Al₂O₃) nanoparticles, T80 lifetimes were 1530h- a little over 2 months. When comparing this to “traditional” silicon cells, which typically last between 20 and 25 years, 63 days may sound like a hopelessly short time, but when we remember that, without these improvements, cells were breaking down in under a week, this ten-fold increase seems- and is- incredible!
This is a big step towards more stable and durable perovskite solar panels. However, there are many other hurdles that Perovskites must overcome before they become common place, which Dr Perera will discuss now:
Georgia:
Wow you put that so well, thank you! I feel like I understand it better now. Besides the current issues with iodine that you mentioned, what other challenges do all-PSCs have to overcome before they could seriously compete with silicon? For example, I have seen people online show hesitations regarding the use of lead- what are your thoughts on that?
Dr. Perera:
Thank you! I’m really glad it helped clarify things.
While iodine leakage is definitely a concern, it’s not the only factor affecting the stability of perovskite solar cells. There are other challenges such as ion migration, degradation caused by heat and UV exposure, and even issues stemming from other layers in the device stack that come into contact with the perovskite. So yes – there are quite a few things that can go wrong.
That said, there’s been really promising progress on this front. Researchers around the world are working hard to improve stability, and the advances over the past few years have been very encouraging. What used to last only a few hours or days in early research now remains stable for thousands of hours under operational conditions.
As for lead toxicity – that’s a very valid concern. But several studies have shown that the amount of lead that actually leaks from perovskite cells is minimal and considered insignificant. Plus, there’s ongoing work to develop lead-free or reduced-lead alternatives, like the lead-tin perovskites I mentioned earlier. With proper encapsulation and recycling systems, lead-containing perovskites can be managed safely – just like we do with many other electronic devices that contain heavy metals.
Stability is clearly the chief concern when it comes to perovskite commercialisation, but iodine leakage is far from the only culprit for the rapid cell degradation. To be commercially viable, theoretical perovskite cells would have to last at least as long as normal silicon panels (20+ years). There are some stories emerging of small improvements that help increase lifespan (such as Dr. Perera’s research), as well as claims of especially-designed cells with possible lifespans of several years (Zhao, et al., 2022). It will be interesting to see how all these developments are adopted in the coming years and if it is possible to rival silicon-based PV.
Speaking of rivaling silicon, another area where perovskites will struggle is their lack of history. By this I mean, silicon PVs have a long legacy of IEC standard testing, installation training, recycling infrastructure, and mainstream visibility that make them a trustworthy investment for the average consumer. Perovskites, on the other hand, would require more qualifications to install, and will be unknown to the average person interested in installing solar panels in their home. This will affect their commercial viability, particularly if maintenance/installation training is not adopted enthusiastically, and disposal options are limited.
Disposal of solar panels at the end of their lifespan is a hot topic, and recycling technology is constantly improving for silicon and thin-film PV modules, despite the myth that PV modules are not recyclable. In fact, solar panels contain many components such as glass, aluminium, metal, and silicon, that can all be used again. If perovskites were to become widespread, recycling procedures would need to be devised and scaled-up to reduce their environmental impact. As I mentioned in the interview, some are hesitant about the lead content of perovskite solar panels, and, whilst many (including Dr. Perera) are not worried about its presence, proper disposal of panels including lead is fundamental to avoid leakage. This will be an element of perovskite recycling not present in silicon PV recycling that will need to be properly thought-out before perovskites can expand in the market. However, as Dr. Perera explains, we are already disposing safely of other devices containing heavy metals, and there are tin-based perovskites being tested to avoid the use of lead.
3) Future trends
Georgia:
Despite this, do you think that Perovskites have the potential to replace or co-exist with traditional solar panels on a large scale in the future?
Dr. Perera:
Great question – I’d say perovskites have the potential to both coexist with and, in some cases, even replace traditional silicon-based solar panels.
Right now, one of the most promising approaches is perovskite-silicon tandem solar cells, where perovskites are layered on top of silicon to boost overall efficiency beyond what either material can achieve alone. Companies like Oxford PV are already deploying this technology commercially, which is a huge step forward. In the longer term, if stability and scalability challenges are fully addressed, all-perovskite solar panels could become a cost-effective alternative on their own. So yes – there’s definitely room for both collaboration and competition on a large scale.
Georgia:
That’s amazing, and so exciting to think that it will be possible thanks in part to your contributions! Still lots to work on though, but I agree the progress so far is promising and the future looks bright (pardon the pun)😅
Whilst perovskite solar panels still have a long way to go before they become an everyday sight like their silicon-based cousins, developments are happening at break-neck pace, and the first commercial perovskite PVs are being piloted right now. Dr. Perera mentioned Oxford PV, a UK-based solar company who recently reported their first commercial installation of perovskite-silicon tandem cells in the US with over 24% efficiency (Oxford PV, 2024), but there are many other firms, such as, QCells, UtmoLight, LONGi, and Caelux, that are working to put all-perovskite or perovskite tandem PV modules on the market as soon as possible.
The developments in this field are fascinating, and some industry experts have predicted several gigawatts of perovskite PV energy capacity to be built by 2026, opening the doors to the growing visibility and commercialisation of perovskite (Wantenaar, 2023). This is certainly a topic that any solar enthusiast should be keeping up with over the coming months!
Read Dr. Perera’s research!
Perera, W.H.K. et al. (2025) ‘Improved stability and electronic homogeneity in perovskite solar cells via a nanoengineered buried oxide interlayer,’ EES Solar, 1(2) pp.115-128. DOI: https://doi.org/10.1039/d4el00029c.
Perera, W.H.K. et al. (2024) ‘23.2% efficient low band gap perovskite solar cells with cyanogen management,’ Energy & Environmental Science, 18(1), pp. 439–453. DOI: https://doi.org/10.1039/d4ee03001j
Perera, W.H.K, et al. (2023) ‘Modification of Hydrophobic Self-Assembled Monolayers with Nanoparticles for Improved Wettability and Enhanced Carrier Lifetimes Over Large Areas in Perovskite Solar Cells’, RRL Solar, 7(17). DOI: https://doi.org/10.1002/solr.202300388
References:
Liu, Z., Lin, R., Wei, M. et al.(2025) ‘All-perovskite tandem solar cells achieving >29% efficiency with improved (100) orientation in wide-bandgap perovskites’, Nature Materials. 24, pp. 252–259. DOI: https://doi.org/10.1038/s41563-024-02073-x
Vourvoulias, A. (2025) How Efficient Are Solar Panels in June 2025? Available at:https://www.greenmatch.co.uk/blog/2014/11/how-efficient-are-solar-panels
LONGi, (2025) 34.85%! LONGi Breaks World Record for Crystalline Silicon-Perovskite Tandem Solar Cell Efficiency Again. Available at: https://www.longi.com/en/news/silicon-perovskite-tandem-solar-cells-new-world-efficiency/
Zhao, X., Liu, T., Burlingame, Q., et al. (2022), ‘Accelerated aging of all-inorganic, interface-stabilized perovskite solar cells’, Science, 377(6603), pp. 307-310. DOI:10.1126/science.abn5679
Oxford PV (2024) 20% more powerful tandem solar panels enter commercial use for the first time in the US. Available at: https://www.oxfordpv.com/news/20-more-powerful-tandem-solar-panels-enter-commercial-use-first-time-us
Wantenaar, A. (2023) Commercial perovskites imminent. Available at: https://www.pv-magazine.com/2023/10/31/commercial-perovskites-imminent/#:~:text=Rethink%20Energy%20expects%20several%20gigawatts,technology%20in%20every%20market%20segment
EN – ES Glossary
| EN | ES | Definition |
| PV cell | Celda solar | Smallest element capable of making PV energy. Made of silicon usually. |
| PV module / Solar Panel | Módulo solar | A group of PV cells together. |
| PV array | Arreglo solar | Any amount of PV modules together. |
| Thin-film | Película delgada | A lightweight solar technology made of very thin layers. |
| Solar energy / Photovoltaics (PV) | Energía solar / fotovoltaica | Taking the energy from the sunlight and using it directly to generate electricity. |
| T80 Lifespan | Vida útil (T80) | The amount of time it takes for a solar cell’s efficiency to degrade to 80%. Used to calculate total lifetime by inference. |
| Perovskite | Perovskita | A light-absorbing material, under development in solar cells for its high efficiency, low cost, and easy manufacturing. |
| Direct Current (DC) | Corriente continua (CC) | Electric current that flows in one direction; produced by solar panels and batteries. Usually converted to AC for use. |
| Alternating Current (AC) | Corriente alterna (CA) | Electric current that changes direction periodically; used in homes and power grids. |
| Silicon | Silicio | A common semiconductor material in traditional solar cells. |
Georgia Meakins 
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