Motivated by the oleophobic and electron-withdrawing nature of perfluorocarbons, we explore the effect of a trifluoromethyl coating on lead sulfide quantum dots (PbS QDs) in thin film transistor (TFT) geometry. The low surface energy conferred by the oleophobic perfluorocarbons creates QDs packed in a primitive cubic lattice with long range order, as confirmed by grazing incidence small angle X-ray scattering (GISAXS) and transmission electron microscopy (TEM). Hole mobilities as high as 0.085 cm2 V-1 s-1 were measured in the TFTs. No electron transport was observed. This suggests that the electron-withdrawing nature of the trifluoromethyl ligand is eclipsed by the excess holes present in the PbS QDs that likely stem from cation vacancies induced by the thiol group.
|Number of pages||8|
|State||Published - May 28 2020|
Bibliographical noteFunding Information:
M. L. T. is grateful for the financial support from SAIT. Y. D. acknowledges partial support from the 3M Nontenured Faculty Award and JITRI International Fellowship. Z. L. and K. R. G. contributed the UPS measurements under work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences and the EPSCoR program, under Award Number DE-SC0018208. The authors thank Prof. Yongtao Cui for use of his atomic force microscope instrument and Xiong Huang’s help in obtaining AFM image. Electron microscopy was performed on a FEI Titan Themis 300 in CFAMM at UC Riverside. This research used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. We gratefully acknowledge the assistance and advice of Dr Byeongdu Lee and Dr Alexis Quental and at the X-ray Science Division beamlines 12-ID-B at the Advanced Photon Source, Argonne National Laboratory.
© 2020 The Royal Society of Chemistry.
ASJC Scopus subject areas
- Materials Science (all)