Breakthrough Stabilizes Perovskite Solar Cells Under Reverse Bias Stress
A new study has found a way to improve the stability of perovskite solar cells under reverse bias. These cells are known for their high efficiency and low production costs, but instability issues have held back their commercial use. Researchers have now developed a method that could make them more reliable and scalable. The problem begins with indium tin oxide (ITO), a common material in these solar cells. Under reverse bias, it triggers an electrochemical reaction that deprotonates the perovskite structure, weakening performance over time. This instability has been a major barrier to large-scale production.
To tackle this, a team led by Wang, Luo, and Li created a molecular-templated pre-assembly method. This approach forms uniform, dense self-assembled monolayers (SAMs) for the hole transport layers. The improved layers boosted efficiency and durability. Testing showed promising results. Small-area devices kept 95% of their initial efficiency after 300 hours under a reverse bias of -4.8 V. Larger minimodules achieved a certified steady-state efficiency of 23.2%. They also maintained 98% of their peak performance for 312 hours under negative open-circuit voltage stress. The team also integrated bypass diodes into the module design. This addition improved safety and extended the lifespan of the solar cells.
The study provides a clear method for addressing electrochemical degradation in thin-film solar technology. By stabilising perovskite cells under reverse bias, the research moves the technology closer to commercial use. The findings also set a benchmark for future work on interfacial stability in photovoltaics.
