Role of microstructure in the electron-hole interaction of hybrid lead halide perovskites

Giulia Grancini, Ajay Ram Srimath Kandada, Jarvist M. Frost, Alex J. Barker, Michele De Bastiani, Marina Gandini, Sergio Marras, Guglielmo Lanzani, Aron Walsh, Annamaria Petrozza

Research output: Contribution to journalArticle

155 Citations (Scopus)

Abstract

Organic-inorganic metal halide perovskites have demonstrated high power conversion efficiencies in solar cells and promising performance in a wide range of optoelectronic devices. The existence and stability of bound electron-hole pairs in these materials and their role in the operation of devices with different architectures remains a controversial issue. Here we demonstrate, through a combination of optical spectroscopy and multiscale modelling as a function of the degree of polycrystallinity and temperature, that the electron-hole interaction is sensitive to the microstructure of the material. The long-range order is disrupted by polycrystalline disorder and the variations in electrostatic potential found for smaller crystals suppress exciton formation, while larger crystals of the same composition demonstrate an unambiguous excitonic state. We conclude that fabrication procedures and morphology strongly influence perovskite behaviour, with both free carrier and excitonic regimes possible, with strong implications for optoelectronic devices.

Original languageEnglish
Pages (from-to)695-701
Number of pages7
JournalNature Photonics
Volume9
Issue number10
DOIs
Publication statusPublished - 2015 Sep 29

    Fingerprint

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics

Cite this

Grancini, G., Srimath Kandada, A. R., Frost, J. M., Barker, A. J., De Bastiani, M., Gandini, M., Marras, S., Lanzani, G., Walsh, A., & Petrozza, A. (2015). Role of microstructure in the electron-hole interaction of hybrid lead halide perovskites. Nature Photonics, 9(10), 695-701. https://doi.org/10.1038/nphoton.2015.151