The sulfolane additive process provides easy manufacturing, low cost, superior performance, and long service life.
A new and simpler solution for making stable perovskite solar cells overcomes the key bottleneck to large-scale production and commercialization of this promising renewable energy technology, which has been tantalizingly out of reach for more than a decade.
“Our work paves the way for low-cost, high-performance commercial-scale production of large-scale solar modules in the near future,” said Wanyi Nie, research scientist at the Center for Integrated Nanotechnologies. Nie is the corresponding author of the article, which was published on March 18, 2021 in the magazine Joule. “We were able to demonstrate the approach through two mini modules that achieved champion levels of converting sunlight to energy with a very extended operational life. Because this process is easy and inexpensive, we believe it can be easily adapted for scalable manufacturing in industrial settings. “
A long-awaited solar technology
Perovskite PV, considered a viable competitor to well-known silicon-based PV on the market for decades, has been a highly anticipated emerging technology for the past decade. Commercialization has been hampered by the lack of a solution to the field’s great challenge: increasing production of high-efficiency perovskite solar cell modules from the tabletop to the factory.
The team, in collaboration with researchers at National Taiwan University (NTU), invented a one-step spin coating method by introducing sulfolane as an additive into the perovskite precursor, or the liquid material that creates the perovskite crystal a through a chemical reaction. As in other manufacturing methods, this crystal is then deposited on a substrate.
The new process allowed the team to produce large-area, high-performance photovoltaic devices that are highly efficient at generating power from sunlight. These perovskite solar cells also have a long service life.
Through a simple dipping method, the team was able to deposit a high-quality, uniform crystalline thin film of perovskite that covered a large active area in two mini-modules, one approximately 16 square centimeters and the other almost 37 square centimeters. Manufacturing a uniform thin film over the entire area of the photovoltaic module is essential for the performance of the device.
Tops in power
The mini modules achieved an energy conversion efficiency of 17.58% and 16.06%, respectively, among the highest reported to date. Energy conversion efficiency is a measure of how efficiently sunlight is converted to electricity.
For other perovskite manufacturing methods, one of the main obstacles to manufacturing on an industrial scale is its narrow processing window, the time during which the film can be placed on the substrate. In order to obtain a uniform crystalline film that is well adhered to the layer below it, the deposition process must be strictly controlled in a matter of seconds.
The use of sulfolane in the perovskite precursor extends the processing window from 9 seconds to 90 seconds, forming tight, highly crystalline layers over a large area and less dependent on processing conditions.
The sulfolane method can be easily adapted to existing industrial manufacturing techniques, helping to pave the way to commercialization.
A perovskite is any material with a particular crystalline structure similar to the mineral perovskite. Perovskites can be designed and manufactured in extremely thin films, making them useful for photovoltaic solar cells.
Reference: “A Simple One-Step Method with a Wide Processing Window” by Hsin-Hsiang Huang, Qi-Han Liu, Hsinhan Tsai, Shreetu Shrestha, Li-Yun Su, Po-Tuan Chen, Yu-Ting Chen, Tso -An Yang, Hsin Lu, Ching-Hsiang Chuang, King-Fu Lin, Syang-Peng Rwei, Wanyi Nie and Leeyih Wang, March 18, 2021, Joule.
DOI: 10.1016 / j.joule.2021.02.012
Funding: This work was conducted, in part, at the Center for Integrated Nanotechnologies, an Office of Science user facility managed for the U.S. Department of Energy (DOE) Office of Science by the U.S. National Laboratory. Alamos (LANL) (Contract 89233218CNA000001). The work done by Shreetu Shrestha and Wanyi Nie was supported by the LANL-LDRD program. Hsinhan Tsai acknowledges the financial support of J. Robert Oppenheimer (JRO) Distinguished Postdoc Fellowship at LANL.