2D Perovskites with Giant Excitonic Optical Nonlinearities for High-Performance Sub-Bandgap Photodetection

Feng Zhou, Ibrahim Abdelwahab, Kai Leng, Kian Ping Loh, Wei Ji

Research output: Journal article publicationJournal articleAcademic researchpeer-review

27 Citations (Scopus)


Two-dimensional (2D) perovskites have proved to be promising semiconductors for photovoltaics, photonics, and optoelectronics. Here, a strategy is presented toward the realization of highly efficient, sub-bandgap photodetection by employing excitonic effects in 2D Ruddlesden–Popper-type halide perovskites (RPPs). On near resonance with 2D excitons, layered RPPs exhibit degenerate two-photon absorption (D-2PA) coefficients as giant as 0.2–0.64 cm MW 1. 2D RPP-based sub-bandgap photodetectors show excellent detection performance in the near-infrared (NIR): a two-photon-generated current responsivity up to 1.2 × 104 cm2 W−2 s−1, two orders of magnitude greater than InAsSbP-pin photodiodes; and a dark current as low as 2 pA at room temperature. More intriguingly, layered-RPP detectors are highly sensitive to the light polarization of incoming photons, showing a considerable anisotropy in their D-2PA coefficients (β[001][011] = 2.4, 70% larger than the ratios reported for zinc-blende semiconductors). By controlling the thickness of the inorganic quantum well, it is found that layered RPPs of (C4H9NH3)2(CH3NH3)Pb2I7 can be utilized for three-photon photodetection in the NIR region.

Original languageEnglish
Article number1904155
JournalAdvanced Materials
Issue number48
Publication statusPublished - 28 Nov 2019
Externally publishedYes


  • 2D Ruddlesden–Popper perovskites
  • excitonic effects
  • nonlinear optics
  • sub-bandgap photodetection
  • two-photon absorption

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

Cite this