| Autor: |
Gilmore RH, Winslow SW, Lee EMY, Ashner MN, Yager KG; Center for Functional Nanomaterials , Brookhaven National Laboratory , Upton , New York 11973 , United States., Willard AP, Tisdale WA |
| Jazyk: |
angličtina |
| Zdroj: |
ACS nano [ACS Nano] 2018 Aug 28; Vol. 12 (8), pp. 7741-7749. Date of Electronic Publication: 2018 Jul 16. |
| DOI: |
10.1021/acsnano.8b01643 |
| Abstrakt: |
In semiconductors, increasing mobility with decreasing temperature is a signature of charge carrier transport through delocalized bands. Here, we show that this behavior can also occur in nanocrystal solids due to temperature-dependent structural transformations. Using a combination of broadband infrared transient absorption spectroscopy and numerical modeling, we investigate the temperature-dependent charge transport properties of well-ordered PbS quantum dot (QD) solids. Contrary to expectations, we observe that the QD-to-QD charge tunneling rate increases with decreasing temperature, while simultaneously exhibiting thermally activated nearest-neighbor hopping behavior. Using synchrotron grazing-incidence small-angle X-ray scattering, we show that this trend is driven by a temperature-dependent reduction in nearest-neighbor separation that is quantitatively consistent with the measured tunneling rate. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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