Perovskite-based solar cells are emerging as promising successors to traditional silicon cells. They offer a simpler and cost-effective production process along with excellent performance. Scientists from the Fraunhofer Institute for Solar Energy ISE and the Faculty of Physics at the University of Warsaw have made significant progress in improving the optoelectronic properties of perovskite photovoltaic cells, addressing a key challenge in their widespread adoption.
Over the past two decades, photovoltaics have seen remarkable growth in panel efficiency and installed capacity, increasing a thousandfold since the year 2000. Silicon has been the go-to material for solar panels, but it’s nearing its efficiency limits. Researchers are now exploring innovative solutions to boost efficiency and reduce production costs while being environmentally friendly.
Perovskite-based cells are a frontrunner in meeting these criteria, boasting efficiency above 26% and cost-effectiveness in production. Numerous research institutes worldwide are working on improving their efficiency and durability in various environmental conditions. One challenge is integrating perovskite cells with silicon cells while minimizing losses from reflection and parasitic absorption.
Traditionally, silicon cells are treated with corrosive chemicals to create a microscopic pyramid pattern on their surface, reducing reflection and increasing current generation. However, perovskites are sensitive to many chemicals, leading to less effective planar anti-reflective coatings applied through a gentler sputtering process.
In their research published in Advanced Materials Interfaces, scientists adopted a nanoimprinting method to create an efficient anti-reflective structure resembling a honeycomb atop perovskite solar cells. This technique allows for the production of nanometer-scale structures on large surfaces exceeding 100 cm².
“This approach ensures scalability in the production of large-surface devices, a critical factor in our transition to renewable energy sources,” says Maciej Krajewski, a researcher from the Faculty of Physics at the University of Warsaw. Modified samples using this method demonstrate higher efficiency compared to cells with previously used planar anti-reflective layers.
Another significant discovery is that applying this layer does not damage the perovskite, opening doors for tailored structures. In the past, similar anti-reflective structures were applied as separate layers, a small-scale and potentially damaging process.
Using direct nanoimprinting, it’s now possible to manufacture the entire device on a large scale in a single technological process, reducing overall costs significantly. Moreover, this method is compatible with a tandem configuration, combining silicon and perovskite cells, offering new possibilities. This breakthrough could lead to more efficient photovoltaic devices, utilizing nanoimprinting techniques in their production.
Source: University of Warsaw