Perovskite solar cells are made of materials with a perovskite crystal structure, which are frequently inexpensive and abundant. Improving the stability and scalability of perovskite solar cells for practical use is one of the challenges researchers have faced.
A significant advancement in the evolution of perovskite solar cells recorded by City University of Hong Kong (CityU) researchers will have significant implications for renewable energy development.
The CityU breakthrough paves the way for the commercialization of perovskite solar cells, bringing us one step closer to an energy-efficient future powered by renewable sources.
“The implications of this research are far-reaching, and its potential applications could revolutionize the solar energy industry,” said Professor Zhu Zonglong of the Department of Chemistry at CityU, who collaborated with Professor Li Zhong’an at Huazhong University of Science and Technology.
This breakthrough is critical because it removes a major impediment to the widespread adoption of perovskite solar cells. Our findings have the potential to significantly broaden the use of these cells, pushing their application boundaries to environments and climates where high temperatures have previously been a deterrent.
Professor Zhu
New approach
Perovskite solar cells, known for their high power conversion efficiency, are a promising new frontier in the solar energy landscape. They do, however, have one significant drawback: thermal instability, which means they don’t perform well when exposed to high temperatures. The CityU team created a novel type of self-assembled monolayer, or SAM, and anchored it to a nickel oxide surface as a charge extraction layer.
“Our approach has dramatically improved the thermal robustness of the cells,” Professor Zhu said, adding that thermal stability is a significant barrier to commercializing perovskite solar cells.
“By introducing a thermally robust charge extraction layer, our improved cells retain over 90% of their efficiency, boasting an impressive efficiency rate of 25.6%, even after operated under high temperatures, around (65 degrees Celsius) for over 1,000 hours. This is a milestone achievement,” said Professor Zhu.
Raising the heat shield
The motivation for this research was born from a specific challenge in the solar energy sector: the thermal instability of perovskite solar cells.
“Despite their high power conversion efficiency, these solar cells are like a sports car that runs exceptionally well in cool weather but tends to overheat and underperform on a hot day. This was a significant roadblock preventing their widespread use,” said Professor Zhu.
The CityU team has focused on the self-assembled monolayer (SAM), an essential part of these cells, and envisioned it as a heat-sensitive shield that needed reinforcement.
“We discovered that high-temperature exposure can cause the chemical bonds within SAM molecules to fracture, negatively impacting device performance. So our solution was akin to adding a heat-resistant armor – a layer of nickel oxide nanoparticles, topped by a SAM, achieved through an integration of various experimental approaches and theoretical calculations,” Professor Zhu said.
To counteract this issue, the CityU team introduced an innovative solution: anchoring the SAM onto an inherently stable nickel oxide surface, thereby enhancing the SAM’s binding energy on the substrate. Also, they synthesized a new SAM molecule of their own, creating an innovative molecule that promotes more efficient charge extraction in perovskite devices.
Better efficiency in higher temperatures
The research’s primary outcome is the potential transformation of the solar energy landscape. The team has laid the groundwork for perovskite solar cells to perform efficiently even in high-temperature conditions by improving the thermal stability of these cells with innovatively designed SAMs.
“This breakthrough is critical because it removes a major impediment to the widespread adoption of perovskite solar cells. Our findings have the potential to significantly broaden the use of these cells, pushing their application boundaries to environments and climates where high temperatures have previously been a deterrent,” said Professor Zhu.
The significance of these discoveries cannot be overstated. By enhancing the commercial viability of perovskite solar cells, CityU is not only introducing a new player in the renewable energy market, but it is also laying the groundwork for a potential game-changer that could play a critical role in the global shift toward sustainable and energy-efficient sources.
“This technology, once fully commercialized, could help decrease our dependence on fossil fuels and contribute substantially to combating the global climate crisis,” he said.
