Stabilization of the Cubic Crystalline Phase in Organometal Halide Perovskite Quantum Dots via Surface Energy Manipulation

Som Sarang, Sara Bonabi Naghadeh, Binbin Luo, Parveen Kumar, Edwin Betady, Vincent Tung, Michael Scheibner, Jin Z. Zhang, Sayantani Ghosh*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

19 Scopus citations

Abstract

Surface functionalization of nanoscale materials has a significant impact on their properties. We have demonstrated the effect of different passivating ligands on the crystal phase of organometal halide perovskite quantum dots (PQDs). Using static and dynamic spectroscopy, we studied phase transitions in CH3NH3PbBr3 PQDs ligated with either octylaminebromide (P-OABr) or 3-aminopropyl triethoxysilane (P-APTES). Around 140 K, P-OABr underwent a structural phase transition from tetragonal to orthorhombic, established by the emergence of a higher energy band in the photoluminescence (PL) spectrum. This was not observed in P-APTES, despite cooling down to 20 K. Additionally, time-resolved and excitation power-dependent PL, as well as Raman spectroscopy over a range of 300-20 K, revealed that recombination rates and types of charge carriers involved are significantly different in P-APTES and P-OABr. Our findings highlight how aspects of PQD phase stabilization are linked to nanoscale morphology and the crystal phase diagram.

Original languageEnglish (US)
Pages (from-to)5378-5384
Number of pages7
JournalJournal of Physical Chemistry Letters
Volume8
Issue number21
DOIs
StatePublished - Nov 2 2017
Externally publishedYes

ASJC Scopus subject areas

  • Materials Science(all)

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