But stability remains a major challenge.
In a recent study published in Science in April, researchers discovered a new way to build perovskite solar cells with additives that improve efficiency and lifespan. The cells have withstood 1,500 hours of high heat and humidity in the laboratory.
The problem is how to translate these results into the real world. It’s difficult for researchers to simulate real-world conditions, and silicon has set a high bar, with many manufacturers guaranteeing their modules will retain 80% of their performance for 30 or even 40 years.
In recent field trials, researchers found that perovskite-based cells recovered over 90% of their original levels after a few months. But the loss of almost 10% of a cell’s performance in that period of time will not affect it.
Another problem is that these tests were all done with tiny cells. Scaling up perovskites and producing larger cells that can be strung together to form full-fledged solar panels often results in setbacks in efficiency and lifetime.
Those challenges mean the day when perovskites take over the solar markets isn’t as near or inevitable as some researchers make it out to be, says Green.
Fine-tuning perovskites with methods like adding stabilizers and materials that protect them from the elements could eventually allow these solar cells to last a few decades under normal operating conditions, says Letian Dou, a perovskite researcher at Purdue University. But he predicts it will be a decade or more before perovskites make any significant commercial advances.
Despite the challenges, there is a real need for different types of solar cells. That’s especially true now that demand for solar materials is exploding, says Jenny Chase, head of solar analysis at Bloomberg New Energy Finance.
And perovskites don’t necessarily have to compete directly with silicon because they can be used in tandem cells, where a perovskite layer is stacked on top of a silicon cell. Because the two materials capture different wavelengths of light, they could complement each other.
None of this is likely to happen unless someone can make perovskite solar cells, which are far more stable. But the researchers are certainly not giving up on the promise. As Green puts it, “There’s still a chance someone might actually make it.”