Structure and surface properties of size-tuneable CsPbBr3 nanocrystals
Thomas J N Hooper1, Yanan Fang2, Alasdair A M Brown3,4,5
1Centre of High Field NMR Spectroscopy and Imaging, Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Republic of Singapore. thooper@ntu.edu.sg.
Nanoscale
|September 16, 2021
Summary
This study reveals nanoscale disorder in cesium lead bromide (CsPbBr3) nanocrystals using solid-state NMR. Surface analysis shows Cs-Br enrichment and passivation by specific ligands, confirming CsPbBr3 nanocrystals
Area of Science:
- Materials Science
- Nanotechnology
- Solid-State Chemistry
Background:
- Cesium lead bromide (CsPbBr3) nanocrystals are crucial for optoelectronic applications.
- Understanding their structure-property relationships is essential for device performance.
- Controlled synthesis and surface characterization are key challenges.
Purpose of the Study:
- To characterize the structure and surface chemistry of CsPbBr3 nanocrystals.
- To investigate the role of ligands in nanocrystal formation and stability.
- To establish 133Cs NMR as a sensitive tool for nanocrystal analysis.
Main Methods:
- Solid-state 133Cs NMR spectroscopy and nuclear relaxation studies.
- X-ray Photoelectron Spectroscopy (XPS).
- 133Cs-1H heteronuclear correlation 2D (HETCOR) NMR.
Main Results:
- Identified radially increasing nanoscale disorder within CsPbBr3 nanocrystals.
- Demonstrated that the nanocrystal surface is Cs-Br rich with vacancies.
- Confirmed passivation by didodecyldimethylammonium bromide (DDAB) ligands, with minimal octylphosphonic acid (OPA) remaining.
- Observed structural stability under ambient conditions for up to 6 months.
Conclusions:
- 133Cs NMR is a sensitive method for analyzing nanocrystal size in solid forms.
- The surface chemistry is critical for CsPbBr3 nanocrystal properties.
- CsPbBr3 nanocrystals exhibit good stability, though agglomeration may occur.
