Neither calcium nor titanium: why are perovskite solar cells expected for photovoltaics in the future?
Perovskite cells are a new type of energy source that has emerged in the wave of green energy in recent years. It is not only an emerging force in photovoltaic materials, but also has the potential to become a promising star in the future photovoltaic field. Despite its name, it actually contains neither calcium nor titanium. What is a perovskite solar cell? In layman's terms, a perovskite solar cell is a type of solar cell with perovskite-type metal halide semiconductors as the main component. This may sound like a cumbersome explanation, but it's actually not that hard to understand.
At the end of the day, this is actually a new type of solar cell, and the innovation lies in the use of new materials that have not been used before. When it comes to solar cells, most people should be familiar with it. Nowadays in many parts of our country, both in cities and villages, many places are equipped with solar street lights, and these street lights use solar panels.
Since the beginning of its application, solar cells have gone through three generations of evolution and progress through monocrystalline silicon cells, thin-film cells, and then perovskite cells. Monocrystalline silicon solar cells have been dominating this market, and perovskite solar cells are an emerging product that is currently promising to replace monocrystalline silicon materials.
Perovskite solar cells are extremely tensile "sunlight collectors" that can easily convert sunlight into the electricity we need due to their excellent light absorption and photoelectric conversion efficiency.
How do perovskite solar cells achieve this transformation? How it works can be summed up in one sentence, and that is the "interaction" between photons and electrons. When such a cell is exposed to sunlight, the semiconductor material inside the cell quickly exerts its effect and begins to absorb photons. These absorbed photons will excite the electrons inside the semiconductor, causing them to move away from their original positions and produce free electrons. The location of the electron becomes a hole. These free electrons and holes move along specific trajectories towards the ends of the cell, respectively, to produce an electric current. The resulting current then flows through an external circuit output and is able to provide us with electrical energy. As easy as it sounds, this "interaction" is actually full of challenges. During transport, some of the free electrons may collide with the holes again and subsequently rebind, resulting in a loss of energy.
In the process of developing new materials, there are usually two factors to consider: one is cost, and the other is efficiency. This is one of the advantages of perovskite solar cells over other cells. The secret of its success can be summed up in three aspects: "high efficiency, low cost, and ease of manufacturing".
Perovskite solar cells offer many advantages, but they are striking for their high efficiency. A delicate layer of perovskite minerals captures more than 90% of sunlight and converts it into electricity. Based on the current situation, the laboratory efficiency of perovskite cells has reached 25.8%, which is comparable to that of monocrystalline silicon solar cells, while this efficiency has the potential to be increased to 33% in theory, exceeding the 29.4% of monocrystalline silicon cells. We must not underestimate this insignificant percent, because in practice, there is a mistake in the inch and a deviation in the ruler.
It also has a relatively low production cost. Unlike traditional monocrystalline silicon cells, which are relatively complex and energy-intensive, perovskite cells are different. On the one hand, it has a wide variety of base materials and low costs, which are not limited by rare metals.
On the other hand, the production process of perovskite cells is relatively simple, and all steps from raw materials to modules can be completed in a single factory, which significantly reduces manufacturing costs. Researchers speculate that it could be half as expensive to produce as crystalline silicon cells.
In the energy revolution, perovskite solar cells are reinterpreting the use of solar energy in a new form and becoming a new star with great development potential.
