摘要
The inter-nanocrystal （NC） distance, necking degree, ordering level, and NC surface ligands all affect the electronic and optoelectronic properties of NC solids. Herein, we introduce a unique PbS structure of necking percolative superlattices to exclude the morphological factors and study the effect of ligands on the NC properties. X-ray photoelectron spectroscopy data indicate that 1,2-ethanedithiol （EDT）, oxalic acid, mercaptopropionic acid, and NH4SCN （SCN） ligands were attached to the surface of NCs by substrate-supported Iigand exchange. Field-effect transistors were tested and photodetector measurements were performed to compare these NC solids. An SCN-treated film had the highest mobility and responsivity under high-power intensity irradiation owing to its high carrier density, whereas an EDT-treated film had the lowest mobility, photocurrent, and dark current. These findings introduce new avenues for choosing suitable ligands for NC applications.
The inter-nanocrystal （NC） distance, necking degree, ordering level, and NC surface ligands all affect the electronic and optoelectronic properties of NC solids. Herein, we introduce a unique PbS structure of necking percolative superlattices to exclude the morphological factors and study the effect of ligands on the NC properties. X-ray photoelectron spectroscopy data indicate that 1,2-ethanedithiol （EDT）, oxalic acid, mercaptopropionic acid, and NH4SCN （SCN） ligands were attached to the surface of NCs by substrate-supported Iigand exchange. Field-effect transistors were tested and photodetector measurements were performed to compare these NC solids. An SCN-treated film had the highest mobility and responsivity under high-power intensity irradiation owing to its high carrier density, whereas an EDT-treated film had the lowest mobility, photocurrent, and dark current. These findings introduce new avenues for choosing suitable ligands for NC applications.
基金
Acknowledgements This work was supported financially by Chinese ministry of science and technology （No. 2016YFA0200700）, National Basic Research Program of China （No. 2014CB931801, Z. Y. T.）, National Natural Science Foundation of China （No. 21473044, C. G. L.
Nos. 21475029 and 91427302, Z. Y. T.）, Instrument Developing Project of the Chinese Academy of Sciences （No. YZ201311, Z. Y. T.）, CAS-CSIRO Cooperative Research Program （No. GJHZ1503, Z. Y. T.）, and ＂Strategic Priority Research Program＂ of Chinese Academy of Sciences （No. XDA09040100, Z. Y. T.）.
