Refine
Document Type
Language
- English (9)
Keywords
- Aqueous electrolytes (1)
- Electrochemistry (1)
- GAAS(110) (1)
- GaAs (1)
- Surface engineering (1)
- X-ray photoelectron spectroscopy (XPS) (1)
- aluminum oxide (Al2O3) (1)
- atomic layer deposition (ALD) (1)
- iodine migration (1)
- perovskite solar cells (1)
- stability (1)
Institute
Atomic Layer-Deposited Aluminum Oxide Hinders Iodide Migration and Stabilizes Perovskite Solar Cells
(2020)
Iodide migration causes degradation of the perovskite solar cells. Here,we observe the direct migration of iodide into the hole-transport
layer in a device. We demonstrate that ultrathin room temperature
atomic layer-deposited Al2O3 on the perovskite surface very effectively hinders the migration. The perovskite-Al2O3 interface enables charge transfer across the Al2O3 layer in the solar cells, without causing any drastic changes in the properties of the perovskite absorber. Furthermore, it helps to preserve the initial properties of the perovskite film during exposure to light and air under real operating conditions, and thus, improves the stability of the solar cells. The ultrathin Al2O3 layer deposited at room temperature significantly increases the lifetime of the perovskite solar cells, and we hope this may be a step toward the mass production of stable devices.
Electrochemically-induced oxidation and reduction reactions of UHV-cleaved GaAs(110) surfaces have been studied after emersion under potential control using highresolution synchrotron-induced photoelectron spectroscopy. High quality spectra of the As and Ga core 3d lines and the valence band region have been obtained. Thespectra of the anodic oxide show strong emission of bulk-like Ga2O3 and some As2O3 with the admixture of suboxides and hydroxides. Ga2O3 and As2O3 arecathodically reduced leaving the GaAs surface covered mostly with elemental As, some As-H and remnants of Ga-suboxides and -hydroxides.