Prof. YE Jichun’s team from the Ningbo Institute of Materials Technology and Engineering (NIMTE) of the Chinese Academy of Sciences (CAS) has developed a novel multifunctional cage-like diammonium chloride molecule. This molecule effectively minimizes interfacial energy losses, enabling the resulting perovskite/silicon tandem solar cells (TSCs) to achieve excellent efficiency and high stability.
The study was published in Nature Communications.
TSCs hold great promise for the photovoltaic industry due to their theoretically ultra-high efficiency and cost advantages, attracting considerable research interest.
Despite a theoretical efficiency limit of 45.1%, significant room for improvement remains, particularly for wide-bandgap (WBG) perovskite top cells. A major obstacle to approaching this limit is the substantial interfacial energy losses at the perovskite/electron-selective contact interface.
To address this bottleneck, researchers at NIMTE synthesized a novel multifunctional cage-like diammonium chloride molecule and inserted it into the perovskite/C60 interface. It can reduce film defects and modulate the interfacial dipole, thus minimizing interfacial energy losses.
Using this approach, the team fabricated 1.68 eV perovskite solar cells that achieved impressive power conversion efficiencies (PCEs) of 22.6% on 0.1 cm2 and 21.0% on 1.21 cm2 active areas.
When integrated into a 1.0 cm2 monolithic perovskite/silicon TSC, this top perovskite solar cell enabled a remarkable PCE of 31.1%. In addition, the tandem device can retain 85% of its initial efficiency after 1,020 hours of continuous maximum power point tracking under ambient conditions, indicating excellent long-term operational stability.
By resolving the critical interface issue, this work paves the way for efficient and stable perovskite-based tandem photovoltaics.
The cage-like molecule enables high-performance perovskite/silicon tandem solar cells (Image by NIMTE)
Contact
YING Zhiqin
Ningbo Institute of Materials Technology and Engineering
E-mail: yingzhiqin@nimte.ac.cn