Silicon solar panels have been in use for nearly 50 years. Since their inception in the mid-20th century, the efficiency of silicone solar has increased from 2% to around 20% (with the highest-end models reaching efficiencies of almost 30%) and cost of production has plunged nearly 98%.
Still, the future of solar energy may not be in silicon at all. Silicon carries a heavy environmental impact, and though it has become more affordable, its fabrication remains expensive relative to other energy sources.
In 2009, researchers in Japan developed a different type of solar cell using a crystalline material called perovskite. Once it was recognized for its impressive light absorption and charge transport properties, perovskite quickly gained ground as a promising material for solar cell research.
Paired with a layer of lead or tin halide, perovskite cells have already exceeded the efficiencies of leading silicon cells by about 4%. One company, the UK-based Oxford PV, has even announced the development of perovskite cells that can convert as much as 37% of the sunlight they absorb into light.
The efficiency of perovskite solar isn’t the only thing about it that holds promise. Perovskites, unlike rigid silicone solar panels, can be painted or sprayed almost anywhere, creating the potential for a type of ‘solar paint’ from the realms of speculative science fiction.
Like silicon solar cells, perovskite cells consist of several of thin films. Thus, researchers have successfully adapted the equipment used in solar cell production and research, including pulsed-DC magnetron sputtering and thermal evaporation systems, as perovskite equipment.
The production of perovskite solar cells is precise, expensive, and still subject to much experimentation. Every variable, from deposition rate to gas pressure, must be carefully controlled and calibrated. Current perovskite equipment set-ups range from small evaporators with a single deposition chamber to multi-chambered clusters. Though researchers have made strides in the replicability of these systems, they are not yet equipped for the mass production.
It would be an understatement to say that researchers are excited about perovskites. Billions in investments have poured into the industry in recent years, and many are pointing to perovskites as the solution to the world’s growing energy crisis. However, there is still much to be done before perovskite solar technology reaches the point at which it is ready for mass commercialization.
Still, the rapid progress in perovskite research in the past decade has researchers hopeful that the technology could one day stand alongside silicon as a viable renewable energy solution.