Proceedings of Online Meetup: Contemporary Stability Challenges in Hybrid Perovskite Photovoltaics (SCHP)
Publication date: 14th April 2020
Engineering two-/three- dimensional (2D/3D) perovskite solar cells is nowadays a popular strategy for efficient and stable devices 1-3. However, the exact function of the 2D/3D interface in controlling the long-term device behavior is still obscure.
Here, we reveal a dynamical structural mutation of the 2D/3D interface: the small cations in the 3D cage move towards the 2D layer, which acts as an ion scavenger. If structurally stable, the 2D physically blocks the ion movement at the interface boosting the device stability. Otherwise, the 2D embeds them, dynamically self-transforming into a quasi-2D structure. 2
2D perovskite acts as a sheath to physically protect the 3D underneath. In concomitance, we discovered that the stable 2D perovskite can block ion movement, improving the interface stability on a slow time scale. 2
The judicious choice of the 2D constituents is decisive to control the 2D/3D kinetics and improve the device lifetime, opening a new avenue for perovskite interface design.
References
[1] J.-P. Correa-Baena et al., Science 358, 739–744 (2017).
[2] A. Sutanto et al. J. Mater. Chem. A 8, 2343-2348 (2020).
[3] V. Queloz et al. J. Phys. Chem. Lett. 10, 19, 5713-5720 (2019).
I acknowledge the “HY-NANO” project that has received funding from the European Research Council (ERC) Starting Grant 2018 under the European Union’s Horizon 2020 research and innovation programme (Grant agreement No. 802862).