July 23, 2024

New Tandem Solar Cells Achieve Efficiencies over 23%

Engineers and material scientists at Chonnam National University in South Korea have developed new monolithic perovskite hybrid tandem solar cells based on all-inorganic halide perovskites. These solar cells have achieved promising efficiencies of 23%, according to a paper published in Energy & Environmental Science. The researchers aimed to resolve limitations of single junction solar cell designs, such as thermalization loss and transmission loss. To overcome these issues, they fabricated tandem solar cells by stacking two absorbers, wide bandgap (WBG) and narrow bandgap (NBG) materials, with a suitable interconnecting layer (ICL).

Previous solar cell designs based on WBG materials have shown highly promising efficiencies. However, these cells typically rely on organic-inorganic hybrid perovskites, which are not thermally stable and can compromise overall performance. Additionally, many of these solar cells are fabricated using complex processes that are difficult to scale up. To address these challenges, the researchers developed all-inorganic perovskite-based WBG in ambient conditions using a hot-air method, and polymer bulk heterojunction (BHJ)-based NBG for the fabrication of these monolithic tandem solar cells.

The researchers achieved their objective of realizing thermally stable WBG materials that can be processed in ambient conditions and integrated into devices with a simple architecture, such as those with an n-i-p configuration. They used a hot-air assisted spin coating technique to create all-perovskite materials. When integrated into hybrid tandem solar cells with an n-i-p architecture, these materials demonstrated encouraging results. The resulting solar cells achieved an efficiency of 23.07% and retained more than 90% of their initial efficiencies for over 600 hours of operation.

The team implemented an n-i-p device configuration and an ambient air-processed approach, making it simple and suitable for commercialization in the future. These tandem solar cells produced higher efficiency than single junction cells, with a very high open circuit voltage (>2 V), making them suitable for applications such as artificial photosynthesis, agri-voltaic systems, and Internet of Things (IoT) devices.

In future studies, the researchers plan to integrate these materials into tandem solar cells with other designs to further explore their potential. The fabrication approach used in this study could also be adopted by other teams to create robust materials for photovoltaic applications. The team is also planning to implement this concept in triple or multijunction tandem solar cells and scale up their production.

*Note:
1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it