Self-assembly of a robust hydrogen-bonded octylphosphonate network on cesium lead bromide perovskite nanocrystals for light-emitting diodes
We report the self-assembly of an extensive inter-ligand hydrogen-bonding network of octylphosphonates on the surface of cesium lead bromide nanocrystals (CsPbBr3 NCs). The post-synthetic addition of octylphosphonic acid to oleic acid/oleylamine-capped CsPbBr3 NCs promoted the attachment of octylpho...
| Main Authors: | , , , , , , , , , , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2020
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| Subjects: | |
| Online Access: | https://hdl.handle.net/10356/138189 |
| _version_ | 1811687988835385344 |
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| author | Brown, Alasdair Angus Macintyre Hooper, Thomas J. N. Veldhuis, Sjoerd Antonius Chin, Xin Yu Bruno, Annalisa Vashishtha, Parth Tey, Ju Nie Jiang, Liudi Damodaran, Bahulayan Pu, Suan Hui Subodh Gautam Mhaisalkar Mathews, Nripan |
| author2 | School of Materials Science & Engineering |
| author_facet | School of Materials Science & Engineering Brown, Alasdair Angus Macintyre Hooper, Thomas J. N. Veldhuis, Sjoerd Antonius Chin, Xin Yu Bruno, Annalisa Vashishtha, Parth Tey, Ju Nie Jiang, Liudi Damodaran, Bahulayan Pu, Suan Hui Subodh Gautam Mhaisalkar Mathews, Nripan |
| author_sort | Brown, Alasdair Angus Macintyre |
| collection | NTU |
| description | We report the self-assembly of an extensive inter-ligand hydrogen-bonding network of octylphosphonates on the surface of cesium lead bromide nanocrystals (CsPbBr3 NCs). The post-synthetic addition of octylphosphonic acid to oleic acid/oleylamine-capped CsPbBr3 NCs promoted the attachment of octylphosphonate to the NC surface, while the remaining oleylammonium ligands maintained the high dispersability of the NCs in non-polar solvent. Through powerful 2D solid-state 31P–1H NMR, we demonstrated that an ethyl acetate/acetonitrile purification regime was crucial for initiating the self-assembly of extensive octylphosphonate chains. Octylphosphonate ligands were found to preferentially bind in a monodentate mode through P–O−, leaving polar P[double bond, length as m-dash]O and P–OH groups free to form inter-ligand hydrogen bonds. The octylphosphonate ligand network strongly passivated the nanocrystal surface, yielding a fully-purified CsPbBr3 NC ink with PLQY of 62%, over 3 times higher than untreated NCs. We translated this to LED devices, achieving maximum external quantum efficiency and luminance of 7.74% and 1022 cd m−2 with OPA treatment, as opposed to 3.59% and 229 cd m−2 for untreated CsPbBr3 NCs. This represents one of the highest efficiency LEDs obtained for all-inorganic CsPbBr3 NCs, accomplished through simple, effective passivation and purification processes. The robust binding of octylphosphonates to the perovskite lattice, and specifically their ability to interlink through hydrogen bonding, offers a promising passivation approach which could potentially be beneficial across a breadth of halide perovskite optoelectronic applications. |
| first_indexed | 2024-10-01T05:25:04Z |
| format | Journal Article |
| id | ntu-10356/138189 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T05:25:04Z |
| publishDate | 2020 |
| record_format | dspace |
| spelling | ntu-10356/1381892021-05-01T20:11:36Z Self-assembly of a robust hydrogen-bonded octylphosphonate network on cesium lead bromide perovskite nanocrystals for light-emitting diodes Brown, Alasdair Angus Macintyre Hooper, Thomas J. N. Veldhuis, Sjoerd Antonius Chin, Xin Yu Bruno, Annalisa Vashishtha, Parth Tey, Ju Nie Jiang, Liudi Damodaran, Bahulayan Pu, Suan Hui Subodh Gautam Mhaisalkar Mathews, Nripan School of Materials Science & Engineering Energy Research Institute @ NTU (ERI@N) Singapore Institute of Manufacturing Technology Engineering::Materials Perovskite Light‐emitting Diodes We report the self-assembly of an extensive inter-ligand hydrogen-bonding network of octylphosphonates on the surface of cesium lead bromide nanocrystals (CsPbBr3 NCs). The post-synthetic addition of octylphosphonic acid to oleic acid/oleylamine-capped CsPbBr3 NCs promoted the attachment of octylphosphonate to the NC surface, while the remaining oleylammonium ligands maintained the high dispersability of the NCs in non-polar solvent. Through powerful 2D solid-state 31P–1H NMR, we demonstrated that an ethyl acetate/acetonitrile purification regime was crucial for initiating the self-assembly of extensive octylphosphonate chains. Octylphosphonate ligands were found to preferentially bind in a monodentate mode through P–O−, leaving polar P[double bond, length as m-dash]O and P–OH groups free to form inter-ligand hydrogen bonds. The octylphosphonate ligand network strongly passivated the nanocrystal surface, yielding a fully-purified CsPbBr3 NC ink with PLQY of 62%, over 3 times higher than untreated NCs. We translated this to LED devices, achieving maximum external quantum efficiency and luminance of 7.74% and 1022 cd m−2 with OPA treatment, as opposed to 3.59% and 229 cd m−2 for untreated CsPbBr3 NCs. This represents one of the highest efficiency LEDs obtained for all-inorganic CsPbBr3 NCs, accomplished through simple, effective passivation and purification processes. The robust binding of octylphosphonates to the perovskite lattice, and specifically their ability to interlink through hydrogen bonding, offers a promising passivation approach which could potentially be beneficial across a breadth of halide perovskite optoelectronic applications. NRF (Natl Research Foundation, S’pore) Accepted version 2020-04-28T05:26:12Z 2020-04-28T05:26:12Z 2019 Journal Article Brown, A. A. M., Hooper, T. J. N., Veldhuis, S. A., Chin, X. Y., Bruno, A., Vashishtha, P., . . . Mathews, N. (2019). Self-assembly of a robust hydrogen-bonded octylphosphonate network on cesium lead bromide perovskite nanocrystals for light-emitting diodes. Nanoscale, 11(25), 12370-12380. doi:10.1039/C9NR02566A 2040-3364 https://hdl.handle.net/10356/138189 10.1039/C9NR02566A 25 11 12370 12380 en Nanoscale https://doi.org/10.21979/N9/GAPRHL © 2019 The Royal Society of Chemistry. All rights reserved. This paper was published in Nanoscale and is made available with permission of The Royal Society of Chemistry. application/pdf |
| spellingShingle | Engineering::Materials Perovskite Light‐emitting Diodes Brown, Alasdair Angus Macintyre Hooper, Thomas J. N. Veldhuis, Sjoerd Antonius Chin, Xin Yu Bruno, Annalisa Vashishtha, Parth Tey, Ju Nie Jiang, Liudi Damodaran, Bahulayan Pu, Suan Hui Subodh Gautam Mhaisalkar Mathews, Nripan Self-assembly of a robust hydrogen-bonded octylphosphonate network on cesium lead bromide perovskite nanocrystals for light-emitting diodes |
| title | Self-assembly of a robust hydrogen-bonded octylphosphonate network on cesium lead bromide perovskite nanocrystals for light-emitting diodes |
| title_full | Self-assembly of a robust hydrogen-bonded octylphosphonate network on cesium lead bromide perovskite nanocrystals for light-emitting diodes |
| title_fullStr | Self-assembly of a robust hydrogen-bonded octylphosphonate network on cesium lead bromide perovskite nanocrystals for light-emitting diodes |
| title_full_unstemmed | Self-assembly of a robust hydrogen-bonded octylphosphonate network on cesium lead bromide perovskite nanocrystals for light-emitting diodes |
| title_short | Self-assembly of a robust hydrogen-bonded octylphosphonate network on cesium lead bromide perovskite nanocrystals for light-emitting diodes |
| title_sort | self assembly of a robust hydrogen bonded octylphosphonate network on cesium lead bromide perovskite nanocrystals for light emitting diodes |
| topic | Engineering::Materials Perovskite Light‐emitting Diodes |
| url | https://hdl.handle.net/10356/138189 |
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