Journal
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
Volume 133, Issue 39, Pages 15753-15761Publisher
AMER CHEMICAL SOC
DOI: 10.1021/ja206303g
Keywords
-
Categories
Funding
- NSF [DMS-0935165]
- NSF-CBET [CBET-0854226]
- NSF MRSEC [DMR-0520020]
- U.S. Department of Energy Office of Basic Energy Sciences, Division of Materials Science and Engineering [DE-SC0002158]
- NSF-IGERT [DGE-0221664]
- Office of Naval Research MURI [ONR-N00014-10-1-0942]
- Department of Energy, DOE Office of ARPA-E [DE-AR0000123]
- Direct For Mathematical & Physical Scien
- Division Of Mathematical Sciences [0935165] Funding Source: National Science Foundation
- Division Of Materials Research
- Direct For Mathematical & Physical Scien [1120901] Funding Source: National Science Foundation
Ask authors/readers for more resources
Ammonium thiocyanate (NH4SCN) is introduced to exchange the long, insulating ligands used in colloidal nanocrystal (NC) synthesis. The short, air-stable, environmentally benign thiocyanate ligand electrostatically stabilizes a variety of semiconductor and metallic NCs in polar solvents, allowing solution-based deposition of NCs into thin-film NC solids. NH4SCN is also effective in replacing ligands on NCs after their assembly into the solid state. The spectroscopic properties of this ligand provide unprecedented insight into the chemical and electronic nature of the surface of the NCs. Spectra indicate that the thiocyanate binds to metal sites on the NC surface and is sensitive to atom type and NC surface charge. The short, thiocyanate ligand gives rise to significantly enhanced electronic coupling between NCs as evidenced by large bathochromic shifts in the absorption spectra of CdSe and CdTe NC thin films and by conductivities as high as (2 +/- 0.7) x 10(3) Omega(-1) cm(-1) for Au NC thin films deposited from solution. NH4SCN treatment of PbTe NC films increases the conductivity by 10(13), allowing the first Hall measurements of nonsintered NC solids, with Hall effect mobilities of 2.8 +/- 0.7 cm(2)/(V.s). Thiocyanate-capped CdSe NC thin films form photodetectors exhibiting sensitive photoconductivity of 10(-5) Omega(-1) cm(-1) under 30 mW/cm(2) of 488 nm illumination with I-photo/I-dark > 10(3) and form n-channel thin-film transistors with electron mobilities of 1.5 +/- 0.7 cm(2)/(V.s), a current modulation of >10(6), and a subthreshold swing of 0.73 V/decade.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available