Interlayer-Spacing Engineering of Lead-Free Perovskite Single Crystal for High-Performance X-Ray Imaging

Ming Chen, Xiaofeng Dong, Depeng Chu, Binxia Jia, Xiaojie Zhang, Zeqin Zhao, Jinglu Hao, Yunxia Zhang, Jiangshan Feng, Xiaodong Ren, Yuqian Liang, Ruixin Shi, Adel Najar, Yucheng Liu, Shengzhong Liu

Research output: Contribution to journalArticlepeer-review

20 Citations (Scopus)


Lead-free A3Bi2I9-type perovskites are demonstrated as a class of promising semiconductors for high-performance X-ray detection due to their high bulk resistivity and strong X-ray absorption, as well as reduced ion migration. However, due to their long interlamellar distance along their c-axis, their limited carrier transport along the vertical direction is a bottleneck for their detection sensitivity. Herein, a new A-site cation of aminoguanidinium (AG) with all-NH2 terminals is designed to shorten the interlayer spacing by forming more and stronger N H···I hydrogen bonds. The prepared large AG3Bi2I9 single crystals (SCs) render shorter interlamellar distance for a larger mobility-lifetime product of 7.94 × 10−3 cm2 V−1, which is three times higher than the value measured on the best MA3Bi2I9 SC (2.87 × 10−3 cm2 V−1). Therefore, the X-ray detectors fabricated on the AG3Bi2I9 SC exhibit high sensitivity of 5791 uC Gy−1 cm−2, a low detection limit of 2.6 nGy s−1, and a short response time of 690 µs, all of which are far better than those of the state-of-the-art MA3Bi2I9 SC detectors. The combination of high sensitivity and high stability enables astonishingly high spatial resolution (8.7 lp mm−1) X-ray imaging. This work will facilitate the development of low-cost and high-performance lead-free X-ray detectors.

Original languageEnglish
Article number2211977
JournalAdvanced Materials
Issue number18
Publication statusPublished - May 4 2023


  • X-ray imaging
  • halide perovskites
  • interlayer-spacing
  • lead-free
  • single crystals

ASJC Scopus subject areas

  • General Materials Science
  • Mechanics of Materials
  • Mechanical Engineering


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