Molecularly thin two-dimensional hybrid perovskites with tunable optoelectronic properties due to reversible surface relaxation

Kai Leng, Ibrahim Abdelwahab, Ivan Verzhbitskiy, Mykola Telychko, Leiqiang Chu, Wei Fu, Xiao Chi, Na Guo, Zhihui Chen, Zhongxin Chen, Chun Zhang, Qing Hua Xu, Jiong Lu, Manish Chhowalla, Goki Eda, Kian Ping Loh

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Abstract

Due to their layered structure, two-dimensional Ruddlesden–Popper perovskites (RPPs), composed of multiple organic/inorganic quantum wells, can in principle be exfoliated down to few and single layers. These molecularly thin layers are expected to present unique properties with respect to the bulk counterpart, due to increased lattice deformations caused by interface strain. Here, we have synthesized centimetre-sized, pure-phase single-crystal RPP perovskites (CH3(CH2)3NH3)2(CH3NH3)n−1PbnI3n+1 (n = 1–4) from which single quantum well layers have been exfoliated. We observed a reversible shift in excitonic energies induced by laser annealing on exfoliated layers encapsulated by hexagonal boron nitride. Moreover, a highly efficient photodetector was fabricated using a molecularly thin n = 4 RPP crystal, showing a photogain of 105 and an internal quantum efficiency of ~34%. Our results suggest that, thanks to their dynamic structure, atomically thin perovskites enable an additional degree of control for the bandgap engineering of these materials.

Original languageEnglish
Pages (from-to)908-914
Number of pages7
JournalNature Materials
Volume17
Issue number10
DOIs
Publication statusPublished - Oct 1 2018

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ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Cite this

Leng, K., Abdelwahab, I., Verzhbitskiy, I., Telychko, M., Chu, L., Fu, W., Chi, X., Guo, N., Chen, Z., Chen, Z., Zhang, C., Xu, Q. H., Lu, J., Chhowalla, M., Eda, G., & Loh, K. P. (2018). Molecularly thin two-dimensional hybrid perovskites with tunable optoelectronic properties due to reversible surface relaxation. Nature Materials, 17(10), 908-914. https://doi.org/10.1038/s41563-018-0164-8