1-Octanol Is a Functional Impurity Modifying Particle Size and Photophysical Properties of Colloidal ZnCdSSe/ZnS Nanocrystals

Unluturk S. S., Cagir A., Varlikli C., Ozcelik S.

JOURNAL OF PHYSICAL CHEMISTRY C, vol.125, no.26, pp.14401-14408, 2021 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 125 Issue: 26
  • Publication Date: 2021
  • Doi Number: 10.1021/acs.jpcc.1c01676
  • Journal Name: JOURNAL OF PHYSICAL CHEMISTRY C
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Chimica, Compendex
  • Page Numbers: pp.14401-14408
  • Middle East Technical University Affiliated: No

Abstract

Impurities in trioctylphophine (TOP) strongly affect nanocrystal synthesis. 1-Octanol among other contaminants in TOP is identified for the first time as a functional impurity by H-1 NMR. The deliberate addition of 1-octanol into trioctylphosphine reduced particle size and modified photophysical properties of ZnCdSSe/ZnS colloidal nanocrystals. NMR analysis furthermore revealed that 1-octanol is bonded to the nanocrystal surfaces. The ratio of integrals for the O-CH2 protons of 1-octanol, which is the lowest compared to the other ligands, suggests that 1-octanol plays a critical role to tune the particle size of nanocrystals. The increased amount of 1-octanol added into TOP reduces the particle size from 9.8 to 7.2 nm, causing a progressive blue shift in the UV-vis and PL spectra but leaving the alloy composition unaffected. The rate of nonradiative processes is enhanced with the amount of 1-octanol added into TOP, correlating with higher dislocation density observed in the nanocrystals. As a conclusion, 1-octanol is proposed as a functional impurity that varies particle size and nonradiative photophysical processes in the ZnCdSSe/ZnS colloidal nanocrystals.