Publication date: 22nd July 2026
Surfaces and interfaces play a central role in the stability and performance of halide perovskite optoelectronic devices. However, most first-principles studies of cubic inorganic halide perovskite surfaces still rely on ideal high-symmetry structures. These models neglect the local positional disorder that is intrinsic to these soft and anharmonic materials. Here, we show that local disorder is not only important for bulk properties [1–2], but also has a sizable effect on surface stability and surface electronic properties.
We investigate cubic CsBX3 perovskites (B = Sn or Pb and X = I, Br, or Cl) using density functional theory (DFT). Locally disordered (polymorphous) bulk configurations were generated using the Anharmonic Special Displacement Method proposed by Zacharias et al. [2]. Polymorphous surface slabs were then constructed by repeating the polymorphous bulk supercells along the (001) direction. To reduce self-interaction errors and improve the calculated electronic properties, we applied the DFT-1/2 quasiparticle correction method [3].
For the surfaces, local disorder lowers the surface energy, indicating that polymorphous surfaces are thermodynamically more favorable than their high-symmetry counterparts. It also shifts the absolute valence-band maximum (VBM) downward with respect to the vacuum level. This shift originates from disorder-induced B-X bond elongation and tilting of the BX6 octahedra. The resulting structural distortions stabilize the bulk VBM and modify the surface dipole, leading to a lower absolute VBM.
The calculated VBM trends are strongly affected by the level of theory. Semilocal DFT gives an incorrect trend across the halide series, while DFT-1/2 recovers the trend observed experimentally [4]. Moreover, polymorphous structures give VBM values that are closer to experimental measurements than those obtained from ideal monomorphous structures. These results demonstrate that the polymorphous nature of halide perovskites must be included to describe their surface electronic properties realistically. Our findings identify local disorder as a key design parameter for tuning surface energetics, interfacial band alignment, and device performance.
This research received funding from the Agence Nationale de la Recherche under the
France2030 programme, MINOTAURE project (grant no. ANR-22-PETA-0015). This work
was granted access to the HPC resources of TGCC and IDRIS under the allocations 2026-
A0190906018, 2025-A0170906018, 2024-A0150906018 made by GENCI.
nanoGe is a prestigious brand of successful science conferences that are developed along the year in different areas of the world since 2009. Our worldwide conferences cover cutting-edge materials topics like perovskite solar cells, photovoltaics, optoelectronics, solar fuel conversion, surface science, catalysis and two-dimensional materials, among many others.
Previously nanoGe Spring Meeting (NSM) and nanoGe Fall Meeting (NFM), MATSUS is a multiple symposia conference focused on a broad set of topics of advanced materials preparation, their fundamental properties, and their applications, in fields such as renewable energy, photovoltaics, lighting, semiconductor quantum dots, 2-D materials synthesis, charge carriers dynamics, microscopy and spectroscopy semiconductors fundamentals, etc.
International Conference on Hybrid and Organic Photovoltaics
International Conference on Hybrid and Organic Photovoltaics (HOPV) is celebrated yearly in May. The main topics are the development, function and modeling of materials and devices for hybrid and organic solar cells. The field is now dominated by perovskite solar cells but also other hybrid technologies, as organic solar cells, quantum dot solar cells, and dye-sensitized solar cells and their integration into devices for photoelectrochemical solar fuel production.
Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics
The main topics of the Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics (IPEROP) are discussed every year in Asia-Pacific for gathering the recent advances in the fields of material preparation, modeling and fabrication of perovskite and hybrid and organic materials. Photovoltaic devices are analyzed from fundamental physics and materials properties to a broad set of applications. The conference also covers the developments of perovskite optoelectronics, including light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.
The International Conference on Perovskite Thin Film Photovoltaics Perovskite Photonics and Optoelectronics (NIPHO) is the best place to hear the latest developments in perovskite solar cells as well as on recent advances in the fields of perovskite light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.