Novel Cathode Interlayer Boosts Performance of Tin-Lead Perovskite Solar Cells
by Riko Seibo
Ulsan, South Korea (SPX) Jan 23, 2024
A team of researchers from the School of Energy and Chemical Engineering at UNIST, led by Professors Sung-Yeon Jang, Jungki Ryu, and Ji-Wook Jang, in collaboration with Professor Sang Kyu Kwak from Korea University, have made notable advancements in the field of perovskite solar cells (PSCs). Their recent work, focusing on enhancing both the stability and efficiency of these cells, could be a significant step towards their broader commercial use.
Perovskite solar cells have drawn attention in the solar energy sector due to their high efficiency and potential for low production costs. However, the commercial viability of PSCs has been hindered by their susceptibility to rapid degradation, primarily caused by environmental factors such as moisture, heat, and light.
Addressing this crucial issue, the team’s research centered around tin-lead halide perovskites (TLHPs). These materials are known for their broad light absorption capabilities but suffer from inherent ionic vacancies that lead to accelerated degradation through inward metal diffusion. To combat this, the researchers developed a chemically protective cathode interlayer using amine-functionalized perylene diimide (PDINN). This novel approach leverages the nucleophilic sites of PDINN to form tridentate metal complexes, which effectively extract electrons and suppress inward metal diffusion.
The solution-processed PDINN cathode interlayer showcased remarkable performance in stabilizing TLHP-based photovoltaic (PV) and photoelectrochemical (PEC) devices. In terms of efficiency, the PV device achieved an impressive 23.21%, maintaining over 81% of its efficiency after 750 hours of operation at 60C. Additionally, it retained more than 90% efficiency after 3100 hours at 23 +/- 4C. These figures mark a significant improvement in the stability of PSCs under prolonged operational conditions.
In the realm of green hydrogen production, the TLHP-based PEC devices, when coupled with biomass oxidation, exhibited a bias-free solar hydrogen production rate of 33.0 mA cm-2. This rate is approximately 1.7 times higher than the target set by the U.S. Department of Energy for one-sun hydrogen production. Such a performance not only underscores the efficiency of the developed cells but also highlights their potential in eco-friendly energy production methods.
Professor Jang, elucidating the team’s objectives, stated, “We have dramatically increased the long-term stability of tin-lead PSCs. Our goal is not only to convert light energy into electrical energy but also to develop eco-friendly methods for producing basic chemicals, such as hydrogen, which form the foundation of various industries.”
The team’s work represents a significant advancement in the field of solar energy. By addressing the long-standing issue of stability in perovskite solar cells, they have opened new avenues for their practical application, not just in solar energy conversion but also in sustainable hydrogen production. This dual benefit is particularly relevant in the context of global efforts to transition to more sustainable energy sources.
Overall, the research conducted by the team at UNIST and Korea University brings us a step closer to the broader adoption of perovskite solar cells in various industrial applications. Their creative approach to enhancing both the efficiency and stability of these cells could have lasting impacts on the renewable energy landscape. As the world increasingly looks towards green solutions, developments like these are not only welcome but essential for a sustainable future.