Molecular and Self-Trapped Excitonic Contributions to the Broadband Luminescence in Diamine-Based Low-Dimensional Hybrid Perovskite Systems

Shrreya Krishnamurthy, Rounak Naphade, Wasim J. Mir, Suresh Gosavi, Sudip Chakraborty*, Ramanathan Vaidhyanathan, Satishchandra Ogale

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

40 Scopus citations


The present solid state lighting (SSL) technology is based on using a combination of phosphors to give the desired white light emitting devices. The property of broadband emission from a single phosphor is not only difficult to achieve but also poses a challenge in device fabrication. Hybrid organic–inorganic perovskites especially in low dimensions (2D/1D) are being widely explored for their optoelectronic properties. Few of these materials exhibit broadband emission upon ultraviolet excitation, providing a scope for synthetic engineering in achieving commercially viable single-phosphor materials. In this work, three interesting diammonium-based low-dimensional hybrid perovskites for broadband photoluminescence (PL) are examined. The doubly protonated ethylenediamine-configured monoclinic (P21/n) 1D ribbon assembly (H3NCH2CH2NH3)8(Pb4Br18) · Br6 (1) and the orthorhombic (Pbcm) 2D-twisted octahedral (H3NCH2CH2NH3)(Pb2Cl6) (2) show white luminescence, while the doubly protonated piperazine-configured orthorhombic (Pnnm) 0D dual-octahedral (C4N2H12)4(Pb2Br11) · (Br)(H2O)4 (3) exhibits bluish-white luminescence. Based on the PL of the organic diammonium salt, the time-resolved PL, Raman signatures, and density functional theory (DFT) calculations, it is shown that the broadband luminescence has dual origin: one around 400 nm from diammonium-related molecular fluorescence and another around 516 nm from self-trapped excitons. The structure-specific relative contributions and interplay between the two define the overall character of the broadband luminescence.

Original languageEnglish (US)
Article number1800751
JournalAdvanced Optical Materials
Issue number20
StatePublished - Oct 18 2018

Bibliographical note

Funding Information:
SK would like to thank CSIR for funding. The authors would like to gratefully acknowledge funding support from the DST-CERI, DST Nanomission (thematic unit), UKEIRI, and SUNRISE. The authors also like to thank Angshuman Nag, Pramod Pillai (IISER Pune), S. K. Asha (CSIR-NCL), K. S. Narayan (JNCASR), and their students, as well as Ms. Archana Patil for experimental help and Dr. Aditya Sadhanala (Cambridge) for fruitful discussions. PRACE is acknowledged for computing time.

Publisher Copyright:
© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim


  • hybrid perovskites
  • self-trapped excitons
  • single crystals
  • small molecules
  • white light emission

ASJC Scopus subject areas

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


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