Details
| Original language | English |
|---|---|
| Pages (from-to) | 4593-4601 |
| Number of pages | 9 |
| Journal | Crystal growth & design |
| Volume | 14 |
| Issue number | 9 |
| Publication status | Published - 3 Sept 2014 |
Abstract
Whereas size effects have been investigated extensively and are largely understood, it is significantly more challenging to elucidate how functional properties of semiconductors can be altered and ultimately be improved by a hierarchical nanoarchitecture. For semiconductor applications, such as in photovoltaics or photocatalysis, it is of great importance to learn how to avoid the recombination of photogenerated charge carriers and how to enhance their lifetime. A gas-phase synthesis method is explored, which enables the generation of spherical zinc oxide nanostructures with compact, mesoporous, a special type of core-shell, so-called yolk-shell, or hollow character. The particles with hollow character exhibit an extraordinarily long persistence of photogenerated charge carriers. It is demonstrated that the presence of the ZnO shell and its special orientation with respect to the polar character of the wurtzite lattice represent deciding factors. After photoexcitation, electrons and holes migrate to opposite sides of the interfaces, where they are stabilized. Moreover, photoluminescence thermometry was used to determine the thermal conductivity of the samples, which is lowered by a factor of ∼100 compared with bulk ZnO. The thermal conductivity of this type of nanostructure is found to be only 10 times larger than that of air, and this points toward potential applications as thermoelectrics.
ASJC Scopus subject areas
- Chemistry(all)
- General Chemistry
- Materials Science(all)
- General Materials Science
- Physics and Astronomy(all)
- Condensed Matter Physics
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: Crystal growth & design, Vol. 14, No. 9, 03.09.2014, p. 4593-4601.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Nanoarchitecture Effects on Persistent Room Temperature Photoconductivity and Thermal Conductivity in Ceramic Semiconductors: Mesoporous, Yolk–Shell, and Hollow ZnO Spheres
AU - Dilger, Stefan
AU - Wessig, Martin
AU - Wagner, Markus R.
AU - Reparaz, Juan S.
AU - Torres, Clivia M. Sotomayor
AU - Qijun, Liang
AU - Dekorsy, Thomas
AU - Polarz, Sebastian
N1 - Copyright: Copyright 2014 Elsevier B.V., All rights reserved.
PY - 2014/9/3
Y1 - 2014/9/3
N2 - Whereas size effects have been investigated extensively and are largely understood, it is significantly more challenging to elucidate how functional properties of semiconductors can be altered and ultimately be improved by a hierarchical nanoarchitecture. For semiconductor applications, such as in photovoltaics or photocatalysis, it is of great importance to learn how to avoid the recombination of photogenerated charge carriers and how to enhance their lifetime. A gas-phase synthesis method is explored, which enables the generation of spherical zinc oxide nanostructures with compact, mesoporous, a special type of core-shell, so-called yolk-shell, or hollow character. The particles with hollow character exhibit an extraordinarily long persistence of photogenerated charge carriers. It is demonstrated that the presence of the ZnO shell and its special orientation with respect to the polar character of the wurtzite lattice represent deciding factors. After photoexcitation, electrons and holes migrate to opposite sides of the interfaces, where they are stabilized. Moreover, photoluminescence thermometry was used to determine the thermal conductivity of the samples, which is lowered by a factor of ∼100 compared with bulk ZnO. The thermal conductivity of this type of nanostructure is found to be only 10 times larger than that of air, and this points toward potential applications as thermoelectrics.
AB - Whereas size effects have been investigated extensively and are largely understood, it is significantly more challenging to elucidate how functional properties of semiconductors can be altered and ultimately be improved by a hierarchical nanoarchitecture. For semiconductor applications, such as in photovoltaics or photocatalysis, it is of great importance to learn how to avoid the recombination of photogenerated charge carriers and how to enhance their lifetime. A gas-phase synthesis method is explored, which enables the generation of spherical zinc oxide nanostructures with compact, mesoporous, a special type of core-shell, so-called yolk-shell, or hollow character. The particles with hollow character exhibit an extraordinarily long persistence of photogenerated charge carriers. It is demonstrated that the presence of the ZnO shell and its special orientation with respect to the polar character of the wurtzite lattice represent deciding factors. After photoexcitation, electrons and holes migrate to opposite sides of the interfaces, where they are stabilized. Moreover, photoluminescence thermometry was used to determine the thermal conductivity of the samples, which is lowered by a factor of ∼100 compared with bulk ZnO. The thermal conductivity of this type of nanostructure is found to be only 10 times larger than that of air, and this points toward potential applications as thermoelectrics.
UR - http://www.scopus.com/inward/record.url?scp=84906879088&partnerID=8YFLogxK
U2 - 10.1021/cg500680g
DO - 10.1021/cg500680g
M3 - Article
VL - 14
SP - 4593
EP - 4601
JO - Crystal growth & design
JF - Crystal growth & design
SN - 1528-7483
IS - 9
ER -