Hybrid perovskites have great potential for use in advanced electronic devices like solar cells and LEDs. However, one major issue holding them back is that they don't last as long as needed for widespread commercial use. As these materials age, their performance drops, which is a big problem for both researchers and companies. To tackle this issue, it's important not only to improve the stability of these perovskites but also to develop methods for detecting how they age in real-time. By understanding how these materials degrade over time, we can make them more durable and efficient.
In a recent study, researchers led by Prof. Yiwen Sun at Shenzhen University used the terahertz time-domain spectroscopy to observe the ageing process of perovskites as it happens. This technique is based on the resonant absorption of terahertz waves by phonons in the perovskite. As perovskites age, the intensity of phonon vibration modes associated with the Pb-I bonds decreases, leading to changes in the absorption peaks of terahertz waves at specific frequencies. Therefore, they proposed using the intensity of these terahertz absorption peaks as an indicator to measure the ageing degree of perovskites in real-time. These findings are important because they offer a practical way to track the ageing of perovskites in real-time. This advancement could help bring perovskite-based devices to the market more quickly, making them more reliable and efficient for everyday use. The work entitled "Real-time detection of ageing status of methylammonium lead iodide perovskite thin films by using terahertz time-domain spectroscopy" was published on Frontiers of Optoelectronics (published on July 29, 2024).
