Recently, intense perovskite solar cell research efforts have been devoted to the development of perovskite passivation materials for both bulk and surface. The background is that both performance losses and degradation mechanisms of perovskite solar cells are initiated at grain boundaries and interfaces, where defects and mobile ions tend to accumulate. The introduction of passivation materials in the perovskite precursor solution or at the materials surface can offer a series of benefits, such as; i) enhancing the hydrophobicity of the perovskite surface working against moisture; ii) passivating defects, prolonging charge-carrier lifetimes and suppressing non-radiative recombination losses; iii) engineering the interfaces within perovskite devices, creating more favorable energy level alignments and enhancing charge extraction, as well as reducing charge recombination. iv) inhibiting ion migration. Adequate passivation treatment/engineering of the perovskite materials will thus lead to significant improvement in device performance and device durability.
Dyenamo offers a series of different perovskite passivation materials, including a new category based on sulfonium salts, dimethylphenethylsulfonium iodide (DMPESI), which recently showed a promising stabilisation of the black-phase FAPbI3 system, especially under moist and light-soaking conditions (Nature Energy, 2023, DOI: 10.1038/s41560-023-01421-6).
For larger quantities or other perovskite passivation materials than the ones displayed in the product descriptions below, please contact us.
It is notable that also salts regularly used as components in the production of perovskite films can be used as passivation materials protecting the film surface. These salts are available under the Dyenamo webpage 'Perovskite salts & additives', but for sake of clarity they are also listed below.
A multifunctional alkylammonium iodide salt containing both R2NH- and R2NH2+-groups on the same six-membered ring, providing both electron-donor and electron-acceptor properties with the ability to react with different surface-terminating ends of perovskite films. The resulting perovskite films, after defect passivation, show relaxed residual surface stress, suppressed nonradiative recombination losses, and more pronounced n-type characteristics for sufficient energy transfer. In addition, PI can work as an electron-transport-layer modifier to replace the unstable LiF for improved device durability under thermal stress.
A multifunctional alkylammonium chloride salt containing both R2NH- and R2NH2+-groups on the same six-membered ring, providing both electron-donor and electron-acceptor properties with the ability to react with different surface-terminating ends of perovskite films. The resulting perovskite films, after defect passivation, show relaxed residual surface stress, suppressed nonradiative recombination losses, and more pronounced n-type characteristics for sufficient energy transfer. In addition, PCl can work as an electron-transport-layer modifier to replace the unstable LiF for improved device durability under thermal stress.
A multifunctional alkylammonium tosylate salt containing both R2NH- and R2NH2+-groups on the same six-membered ring, providing both electron-donor and electron-acceptor properties with the ability to react with different surface-terminating ends of perovskite films. The resulting perovskite films, after defect passivation, show relaxed residual surface stress, suppressed nonradiative recombination losses, and more pronounced n-type characteristics for sufficient energy transfer. In addition, PToS can work as an electron-transport-layer modifier to replace the unstable LiF for improved device durability under thermal stress. The bulk anion ToS- can improve the cell voltage and the stability of perovskite solar cells.
DN-PA04 represents a new approach for surface treatment to stabilize perovskite solar cells. In contrast to the widely developed ammonium salts, this aprotic sulfonium-based molecular material shows weaker interaction with water molecules and stronger interaction with the perovskite film. As a result, the surface treatment with DMPESI dramatically enhances the perovskite film and device stability under different conditions, including moisture, light soaking, and elevated temperature.
4-tert-butyl-benzylammonium iodide is an interface passivator for perovskite solar cells that can significantly accelerate the charge extraction from the perovskite materials into the hole-transporters and reduce device hysteresis as well as improve the device performance and stability.
2-Cyclohexylethylammonium iodide have been used as an interfacial treatment and shown to play a key role in enhancing perovskite solar cell device performance and especially effectively improvement in long-term stability.
ortho-(phenylene)di(ethylammonium) iodide is an effective passivation agent for interfacial treatment between the perovskite and hole transporting layer, which delivers highly efficient and stable PSCs.
Phenethylammonium formate is an effective passivation agent to the surface defects of perovskite, and it could be also employed as spacer cation in two-dimensional halide perovskites to enhance carrier diffusion in the near-surface regions and reduce defect density, which delivers highly efficient and stable PSCs.
DN-P35 (n-octylammonium iodide) (OAI) is one precursor utilized as one spacer layer in 2D or quasi 2D perovskite solar cells, and OAI was also considered as an import modifier in fabrication of high-quality 3D perovskites for photovoltaic devices. Octylammonium cations have been used as encapsulating additive and passivation layer favoring the crystal growing along the preferential crystal orientation without the formation of layered structures in contrast to butylammonium (BA) and phenethylammonium (PEA) cations and reducing non-radiative recombination. (Jung et al., 2018). And OMA has also been deployed for construction of the capping 2D layers to the bulk 3D underlayer in PSCs. Elongated device durability and boosted device efficiency with certified value of 22.9% was achieved. (Jung et al., 2019).
With a purity level > 99% and an extremely low moisture content, Dyenamo's DN-P35 (n-octylammonium iodide, OAI) has a superior quality for stable results and optimal performance.
Alternative name:
OAI
Chemical composition:
C8H20NI
Typical properties:
MW = 257.16 g/mol
References:
M. Jung, T. J. Shin, G. Kim, S. I. Seok, Energy Environ. Sci., 11, 2188, 2018, DOI: 10.1039/C8EE00995C
H. Kim, S.-U. Lee, D. Y. Lee, M. J. Paik, H. Na, J. Lee, S. I. Seok, Adv. Energy Mater., 9, 1902740, 2019, DOI: 10.1002/aenm.201902740
DN-P39 (Phenylammonium iodide, C6H8NI) is an aromatic halide salt used to construct efficient interfacial layer between perovskite and charge transporting layers to passivate the perovskite surface defects and facilitate charge transportation, thereby boosting the device performance and enhancing the device robustness.
DN-P40 (3-Phenylpropylammonium iodide, C9H14NI, PPAI) is a benzene alkylammonium salt precursor widely used to construct perovskite based optoelectronic devices, such as solar cells and light-emitting diodes (LED). With PPAI as surface passivator, effective defect passivation on the perovskite surface and successful iodine migration inhibition have been shown, simultaneously enhancing efficiency and stability in both LED and solar cells devices.
DN-P41 (4-Phenylbutylammonium iodide, C10H16NI, PBAI) is a benzene alkylammonium salt precursor widely used to construct layered two-dimensional perovskites and surface passivator to the defects of perovskites in LED and solar cells devices. PBAI was validated to show profound effects on modulating the charge recombination pathways and inhibiting unfavorable ion migration etc.
