New inverted perovskite solar cell boosts 25% efficiency, 98% stability

Researchers at Zhejiang University in China have engineered an inverted perovskite solar cell using a novel high-entropy hybrid perovskite (HEHP) material. This approach has yielded an improvement in stability, without compromising efficiency.

The HEHP structure is unique due to its highly disordered organic moieties. These moieties contribute to entropy gain and improve thermal stability and structural robustness. Speaking to PV Magazine, the study’s co-author Jingjing Sue explained the team’s findings.

“Our work highlights the potential of a kind of high-entropy structure, namely high entropy hybrid perovskite, in improving the efficiency and stability of perovskite solar,” Sue said.

What sets this new material apart is its multicomponent single-phase perovskite structure. Compared to conventional perovskites, this structure exhibits higher phase stability at high temperatures, confirmed through nuclear magnetic resonance (NMR) spectroscopy.

“The HEHP single crystal showed an ensemble of signature peaks of all the constituent organic cations, which was in good agreement with that of the equimolar mixture of all the five organic cations,” the team explained. This suggests a hybrid structure comprising ordered inorganic frameworks and disordered organic interlayers.

Efficiency and stability like never before

The team constructed a perovskite solar cell using the HEHP film, which, they claim, boasts remarkable water and damp-heat resistance.

Their solar cell architecture includes an indium tin oxide (ITO) substrate, a tin oxide (SnO2) electron transport layer (ETL), the perovskite absorber, a Spiro-OMeTAD hole transport layer, and a silver (Ag) metal contact.

Under standard illumination conditions, the cell achieved a power conversion efficiency of 25.7%, beating the reference device’s 23.2%. The open-circuit voltage reached 1.17 V, while the short-circuit current density and fill factor were 25.8 mA cm² and 85.2%, respectively.

Notably, the HEHP-based cell retained over 98% of its initial efficiency over 98% of its initial efficiency after 1,000 hours of operations. This suggests the cell’s suitability for long-term real-world applications.

The team attributes these improvements to reduced non-radiative recombinations and optimizing the interface resulting from incorporating HEHP. “The superiority of HEHP over a single component in reducing electronic disorders could be attributed to the coexistence of multiple types of A-site cations that can synergistically interact with various defects,” the team told PV Magazine.

Implications for the future of Solar Energy

The research team believes that their novel perovskite material could be widely applicable across different perovskite compositions and cell architectures.

This versatility positions HEHP as a potential universal and error-tolerant strategy for improving perovskite solar cell performance under various conditions and could prove crucial in improving production yields as the industry scales up mass production of perovskite devices.

The research team is optimistic about the future applications of their findings. “It may serve as a highly universal and error-tolerant strategy to improve the performance of perovskite solar cells under various scenarios, which is crucial to improve the production yield of perovskite devices in future industrial mass production,” they told PV Magazine.

With continued research and development, high-entropy hybrid perovskites could help unlock the full potential of solar energy.