Single-Step Synthesis of Cs <sub>3</sub> Bi <sub>2</sub> I <sub>9</sub> Nanocrystals for Scalable Direct X-ray Detectors
Lead-free perovskite-inspired materials have emerged as promising candidates for direct X-ray detection. However, in the early exploration of emerging materials, the focus was on large single crystals. Herein, we report a facile, scalable, single-step synthesis of high-quality Cs<sub>3</sub>Bi<sub>2</sub>I<sub>9</sub> nanocrystals (NCs) directly from their precursor powders through an ultrasonication approach. The large-scale synthesis of the NCs allowed for the production of 0.78 cm<sup>2</sup> pellets used in the fabrication of X-ray detection devices, which exhibit a high bulk resistivity of 1 × 10<sup>11</sup> Ω cm and a low dark current density of 3.3 nA cm<sup>-2</sup> under an applied bias of 50 V (357 V cm<sup>-1</sup> electric field). These devices achieve a limit detection of 108 nGy<sub>air</sub> s<sup>-1</sup>, an order of magnitude improvement over the a-Se used in commercial medical imaging, along with stable current under continuous X-ray exposure with a peak energy of 35 keV<sub>p</sub>. Finally, we demonstrate the scale-up of these detectors by producing thick films 9 cm<sup>2</sup> in area, achieving a performance comparable to that of the detectors based on pellets.
Authors
- Lakshminarayana Polavarapu (ORCID: https://orcid.org/0000-0002-9040-5719)
- Xian Wei Chua (ORCID: https://orcid.org/0000-0003-3015-6834)
- Sara Bals (ORCID: https://orcid.org/0000-0002-4249-8017)
- Nadine J. Schrenker (ORCID: https://orcid.org/0000-0002-3667-4440)
- Yi‐Teng Huang (ORCID: https://orcid.org/0000-0002-4576-2338)
- Kavya Reddy Dudipala
- Robert L. Z. Hoye (ORCID: https://orcid.org/0000-0002-7675-0065)
- Sergio Gómez‐Graña (ORCID: https://orcid.org/0000-0002-7736-051X)
- Joydip Ghosh (ORCID: https://orcid.org/0000-0001-9356-0821)
- Isabel Braddock (ORCID: https://orcid.org/0000-0003-1666-5907)
- Matthew C. Veale (ORCID: https://orcid.org/0000-0001-5457-4884)
- Akshay Rao (ORCID: https://orcid.org/0000-0003-4261-0766)
- Deepika Gaur
- Shiling Dong (ORCID: https://orcid.org/0000-0002-7844-5048)
- Jack M. Woolley (ORCID: https://orcid.org/0000-0002-3893-3880)
- Yixin Wang (ORCID: https://orcid.org/0000-0002-2789-7909)
- Michael Wilson (ORCID: https://orcid.org/0000-0003-0997-0786)
- Ramavath Babu (ORCID: https://orcid.org/0000-0002-9301-4182)
Institutions
- Rutherford Appleton Laboratory (GB)
- University of Antwerp (BE)
- Science and Technology Facilities Council (GB)
- University of Cambridge (GB)
- University of Warwick (GB)
- University of Oxford (GB)
- Centro Universitário de Sete Lagoas (BR)
- Universidade de Vigo (ES)
Publication Details
- Journal
- ACS Energy Letters
- Published
- 2025-11-11
- DOI
- https://doi.org/10.1021/acsenergylett.5c02509
- Primary Topic
- Perovskite Materials and Applications
- Type
- article
- Field-Weighted Citation Impact
- 0.00