"On the way of stabilizing perovskite material: A fundamental study via Scanning Tunneling Microscopy and Photoelectron Spectroscopy"

Who: Jeremy Hieulle, Nanoimaging Group

Place: nanoGUNE seminar room, Tolosa Hiribidea 76, Donostia - San Sebastian

Date: Monday, 11 May 2020, 11:00

In an effort to limit the current spread of COVID-19, all seminars are canceled beginning Thursday March 12th until further notice


On the way of stabilizing perovskite material: A fundamental study via Scanning Tunneling Microscopy and Photoelectron Spectroscopy


Jeremy Hieulle1

1Energy Materials and Surface Sciences Unit (EMSS), Okinawa Institute of Science and Technology Graduate University (OIST), 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan.

*j.hieulle@nanogune.eu 


Organic-inorganic perovskite solar cells are currently under the spotlight. Despite numerous advantages, their poor stability hinders commercialization of perovskite-based devices. To increase perovskite stability various strategies have been envisaged [1]. Mixing different halides (I, Br, Cl) has been shown both experimentally and theoretically to have a strong impact on the device performance and stability [2-5]. However, the stabilizing effect of the halides critically depends on their distribution in the mixed compound, a topic that is currently under intense debate [6-8]. A fundamental understanding remains largely elusive regarding the correlation between the structure of the mixed-perovskites and their electronic properties at the atomic level.


In this work, combining scanning tunneling microscopy (STM), density functional theory (DFT) and UV/X-ray photoelectron spectroscopy (UPS/XPS), we reveal the exact location of I and Cl anions in the mixed CH3NH3PbBr3-yIy and CH3NH3PbBr3-zClz perovskite lattices. Additionally, we demonstrate the impact of halide-incorporation on the material electronic properties and stability. Furthermore, we determine the ideal Cl-incorporation ratio for stability increase without detrimental bandgap modification. The increased material stability induced by chlorine incorporation is verified by performing photoelectron spectroscopy on a device architecture. Our findings provide an important direction for the fabrication of stable perovskite devices.




References:

[1] Noh, J. H.; Im, S. H.; Heo, J. H.; Mandal, T. N.; Seok, S. I., Chemical Management for Colorful, Efficient, and Stable Inorganic?Organic Hybrid Nanostructured Solar Cells. Nano Letters 2013, 13 (4), 1764-1769.

[2] Liu, J.; Prezhdo, O.V. J. Phys. Chem. Lett.  2015, 6 (22), 4463.

[3] Quarti, C.; Mosconi, E.; Umari, P.; De Angelis, F. Inorg. Chem. 2017, 56, 74.

[4] Colella, S.; Mosconi, E.; Pellegrino, G.; Alberti, A.; Guerra, V.L.P.; Masi, S.; Listorti, A.; Rizzo, A.; Condorelli, G.G.; De Angelis, F.; Gigli, G. J. Phys. Chem. Lett.  2014, 5 (20), 3532.

[5] Yu, H.; Wang, F.; Xie, F.; Li, W.; Chen, J.; Zhao, N. Adv. Funct. Mater. 2014, 24, 7102.

[6] Ye, M.; Hong, X.; Zhang, F.; Liu, X. J. Mater. Chem. A 2016, 4, 6755.

[7] Zhang, T.; Yang, M.; Benson, E.E.; Li, Z.; Lagemaat, J.; Luther, J.M.; Yan, Y; Zhu, K; Zhao, Y. Chem. Commun. 2015, 51, 7820.

[8] Luo, S.; Daoud, W.A. Materials 2016, 9, 123.


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