Understanding Optical Properties and Electronic Structures of High‐Entropy Alloyed Perovskite Nanocrystals

Understanding Optical Properties and Electronic Structures of High‐Entropy Alloyed Perovskite Nanocrystals

Angewandte Chemie International Edition

10.1002/anie.202505890

https://doi.org/10.1002/anie.202505890

Yung‐Tai Chiang, Sunil B. Shivarudraiah, Alexander Wieczorek, Khoong Hong Khoo, Zhidong Leong, Jia Wei Melvin Lim, Zengshan Xing, Sudhir Kumar, Simon F. Solari, Yen‐Ting Li, Yu‐Cheng Chiu, Tze Chien Sum, Yun Liu, Sebastian Siol, Chih‐Jen Shih

perovskite

25 July 2025

Chiang, Y.-T., Shivarudraiah, S. B., Wieczorek, A., Khoo, K. H., Leong, Z., Lim, J. W. M., Xing, Z., Kumar, S., Solari, S. F., Li, Y.-T., Chiu, Y.-C., Sum, T. C., Liu, Y., Siol, S., & Shih, C.-J. (2025). Understanding Optical Properties and Electronic Structures of High‐Entropy Alloyed Perovskite Nanocrystals. Angewandte Chemie International Edition, 64(37). Portico. https://doi.org/10.1002/anie.202505890

Abstract High‐entropy alloying (HEA) has emerged as a prominent strategy to modulate physiochemical properties of nanomaterials. Nevertheless, this approach is underexplored in luminescent semiconductor nanocrystals (NCs) due to the lack of understanding into the HEA‐induced electronic effect and photophysical behaviors. Herein, harnessing the defect tolerance of metal halide perovskite NCs, we systematically synthesized and characterized high‐entropy halide perovskite (HEP) NCs containing multiple B‐site elements (Pb 2+ , Sr 2 ⁺, Ca 2 ⁺, Cd 2 ⁺, and Mg 2 ⁺). High‐resolution transmission electron microscopy, transient photoluminescence and absorption spectroscopy, X‐ray photoemission spectroscopy, and density functional theory simulations are employed to unravel the evolution of electronic structures with respect to the alloying degree and link them to the spectral signatures and photostability. Counterintuitively, although the HEP NCs exhibit lateral sizes smaller than the Bohr diameter of CsPbBr 3 NCs (∼7 nm), HEA reduces the band dispersion and broadens the conduction band, thereby vanishing the excitonic feature by forming near band‐edge shallow states. We show that these HEA‐induced shallow states foster rapid radiative recombination and improve photostability, accompanied by a significantly reduced lead content by up to 70%. These findings pioneer the understanding of the correlation between HEA‐induced electronic effect and photophysical properties, highlighting the versatility of HEA for band structure engineering and stabilization of metal halide perovskites NCs.

Publisher Copyright

This research / project is supported by the A*STAR - Career Development Fund
Grant Reference no. : C233312001

This research / project is supported by the A*STAR - Young Achiever Award
Grant Reference no. : NA

This research / project is supported by the National Research Foundation - Competitive Research Programme
Grant Reference no. : NRF-CRP25-2020- 0004

This research / project is supported by the MOE - AcRF Tier 2
Grant Reference no. : MOE-T2EP50120-0004

This research / project is supported by the Ministry of Education - Academic Research Fund Tier 2
Grant Reference no. : MOE-T2EP50123-0001

The authors are grateful for ScopeM (ETH Zürich) for the access to electron microscopy. Y.T.C., S.B.S., A.W., S.K., S.S., and C.J.S. thank funding from the Strategic Focus Area– Advanced Manufacturing (SFA-AM) through the AMYS project and European Research Council (ERC) starting grant (N849229–CQWLED).

This is the peer reviewed version of the following article: Chiang, Y.-T., Shivarudraiah, S. B., Wieczorek, A., Khoo, K. H., Leong, Z., Lim, J. W. M., Xing, Z., Kumar, S., Solari, S. F., Li, Y.-T., Chiu, Y.-C., Sum, T. C., Liu, Y., Siol, S., & Shih, C.-J. (2025). Understanding Optical Properties and Electronic Structures of High‐Entropy Alloyed Perovskite Nanocrystals. Angewandte Chemie International Edition, 64(37). Portico. https://doi.org/10.1002/anie.202505890 , which has been published in final form at https://doi.org/10.1002/anie.202505890. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.

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