Perovskites: The Crystal Revolution That Could Power Tomorrow

By Aruzhan Abdikadyrova

Imagine a material so versatile and flexible, that can be printed out as a thin film, modified to fit any surface, and adapted to form not only highly efficient solar cells, but also transform the entire traditional energy system. That is a reality of perovskites, synthetic compounds, which are revolutionizing solar cell technology today.

So what exactly are perovskites and what makes them so effective for solar uses? The term “perovskite” originates from a naturally occurring mineral, calcium titanate (CaTiO₃), that was found in the Ural Mountains back in 1839. However, today, this word refers to any material that shares its highly flexible crystal structure. This unique atomic arrangement allows scientists to precisely arrange various elements, organic ions, metals, halogens, into the structure, leading to diverse engineered materials with a range of different properties.

When perovskite materials were first explored, their efficiency was about 3%, but in just over a decade, scientists have managed to boost that figure to more than 26%. This rapid progress makes them one of the fastest advancing technologies ever. Perovskites are exceptionally effective at converting light into electricity. They have high-defect tolerance, and they handle heat well, maintaining stable power output even in warm conditions. Their flexible and lightweight nature also enables the use not only for roof panels, but also for curved building surfaces and wearable devices. Unlike silicon, which requires high-energy and high-temperature processes, perovskites can also be made affordably and come in solution form.

Imagine this: instead of needing massive factories, you could practically “print” solar cells! The process of making solar cells with perovskites often starts with the preparation of ink containing perovskite. Low-volume, lab-scale preparation is usually carried out using methods such as spin coating, where they drip the ink onto the spinning surface to create a thin layer. Roll-to-roll techniques (doctor blade or slot-die coating) are suitable for bigger scale processes. These techniques facilitate the formation of efficient thin films from the precursor inks, enabling high output, reduced material waste and lower manufacturing costs.

So, what is the catch? What is holding these promising perovskite solar cells back? No tech comes without its headaches, and perovskites are no exception. The two big ones are stability and the use of lead. The perovskite cells are often sensitive to the heat, moisture, oxygen, and UV radiation. Another concern is associated with the toxicity of the lead in high-efficiency formulations and its possible leakage upon device degradation. Currently, significant research efforts are being conducted to mitigate this issue through advanced encapsulation techniques and the development of lead-free alternatives. Despite those challenges, these materials are clearly set to be a huge part of the future, bringing us closer to the world that is both efficient and sustainable.