A new molecular treatment developed in Hong Kong could be the missing piece in achieving the widespread adoption of perovskite solar panels.
The perovskite problem. Perovskite photovoltaic cells, invented in a Japanese lab in the late 2000s, have generated a lot of buzz in recent years due to their low cost, flexibility, and potentially superior performance compared to conventional silicon cells.
However, the technology remains commercially unavailable due to its instability and short lifetime. Defects in the material limit charge recombination at the physical level.
An effective solution. To overcome this obstacle, a team of researchers in Hong Kong has developed a method that chemically modifies the surface of perovskite cells to eliminate their defects and increase their efficiency and durability.
The scientists found that treating the surface of perovskite photovoltaic cells with specific combinations of amino silanes (chemical compounds in which silicon atoms bond to organic amino groups) significantly improves the cells’ performance and long-term operational stability.
Double the benefit. In this process, known as “passivation,” researchers deposit the amino silanes into the perovskite cells using water vapor.
Passivation has been the preferred approach for scientists trying to improve the efficiency of perovskites. Still, the new method, described by the authors in Science, reduces the voltage deficit to almost the theoretical limit and significantly improves the material’s stability.
New longevity record. The researchers tested the cells at 185 degrees Fahrenheit and 60% relative humidity, simulating extreme conditions in real-world applications. With a design that maximizes the use of the solar spectrum by absorbing different wavelengths in each layer, the passivated cells increased the material’s ability to convert light into energy by a factor of 60.
The researchers achieved an energy conversion efficiency of 20.1% (95% of the original value) after more than 1,500 hours of use. These are the best durability figures ever recorded for perovskite cells.
The light at the end of the tunnel. This breakthrough opens the door to the large-scale use of perovskite photovoltaic cells, starting with their installation on balconies, canopies, and vehicles. Perovskite solar cells are thinner and more flexible than conventional silicon cells and can have a film form. You can use them with other solar cells to increase overall efficiency.
The government of Japan, the birthplace of perovskite cells, has committed more than $400 million to producing perovskite photovoltaic cells and has formed a consortium of 150 companies and organizations to accelerate the introduction of next-generation flexible solar panels.
This article was written by Matías S. Zavia and originally published in Spanish on Xataka.
Images | HKUST, National Renewable Energy Laboratory
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