Perovskite is emerging as a transformative material in the solar energy sector, offering advantages over traditional silicon. Its unique properties make it not only more efficient but also less expensive, opening up possibilities for diverse applications across various surfaces, including windows, facades, vehicles, and even satellites.
The rise of photovoltaic solar energy in recent decades has been driven by several factors, including the urgent need to reduce dependency on fossil fuels, alongside improvements in technology and material science. Among these advancements is perovskite, a material initially discovered in the Ural Mountains of Russia in 1839 by Gustav Rose, named after the Russian mineralogist Lev Perovski. Today”s perovskite refers to synthetic materials with crystal structures that mimic the original mineral, and these can be produced in laboratories using readily available substances such as bromine, chlorine, lead, and tin.
Perovskite is gaining traction as it plays a crucial role in the development of the fourth generation of solar cells. The first generation utilized crystalline or polycrystalline silicon, while the second generation employed materials like selenium and cadmium. The third generation introduced nanomaterials for the first time. A significant breakthrough occurred in 2009 when researchers from the University of Tokyo utilized perovskite as a light-absorbing material, achieving a conversion efficiency of 3.8% at that time. Remarkably, this efficiency has now soared to 25.5%, surpassing the average efficiency of silicon-based cells, which stands at 22%.
According to Professor Eva Ma Barea Berzosa from Universitat Jaume I, the advancements in perovskite technology have occurred at an unprecedented pace. “This material has achieved in just thirteen years what silicon took fifty years to accomplish,” she noted. Moreover, improvements in the material”s stability against environmental factors such as humidity and oxygen mean that perovskite does not degrade within hours, as it once did.
The key advantage of perovskite lies in its exceptional optoelectronic properties. It can convert a larger portion of the light spectrum into energy, thanks to several factors, including the high mobility of electrons within the cells. This results in:
- High efficiency: It can transform a significant portion of the light spectrum into electricity.
- Lower material dependency: Perovskite can be manufactured through simpler chemical processes using more abundant materials compared to silicon.
- Cost-effective production: Its manufacturing process is potentially cheaper and requires less energy than that of solar-grade silicon.
- Versatility: Being lightweight, ultra-thin, semi-transparent, and flexible, these cells can be applied to irregular surfaces, vehicle roofs, and next-generation low-cost satellites.
One of the most promising developments is the combination of perovskite with silicon, which merges the advantages of both materials in solar energy absorption. Flexible cells produced from this combination have achieved remarkable efficiencies of up to 26.7%, and theoretically, efficiencies could reach 33%. The perovskite-silicon tandem cells have demonstrated potential efficiencies exceeding 47% in theory. Each material captures energy from different wavelengths of light, with silicon primarily utilizing red and infrared spectra, while perovskite excels in blue and green light absorption. This synergy allows for nearly complete utilization of solar radiation reaching the Earth.
The IMDEA Nanociencia Institute, a private nonprofit foundation within the Madrid Institute of Advanced Studies network, has highlighted the benefits of perovskite in a recent study published in Advanced Materials. Additionally, a team from Huazhong University of Science and Technology in China reported achieving an impressive efficiency of 28.8% with a perovskite tandem that did not include silicon.
Combining these materials to generate more energy could reduce electricity costs by approximately 10% compared to standard silicon panels, as noted by Oxford PV, a startup that originated at the University of Oxford. This increased efficiency is attributed to the higher energy output per square meter.
Perovskite also presents advantages in the context of global politics. The production of silicon is costly and predominantly controlled by China, whereas perovskite can be produced using a variety of materials. However, it is essential to note that the most expensive component of a solar panel today is its aluminum frame, accounting for a significant portion of the total cost.
Despite its promise, perovskite technology does face challenges. Early generations were prone to rapid degradation when exposed to moisture, oxygen, and high temperatures. Furthermore, the presence of lead—a toxic heavy metal—raises safety concerns. Lastly, maintaining consistency in manufacturing remains a significant hurdle.
