Abstract
Thermoelectric properties of zinc oxide (ZnO) are largely influenced by its electrical property. In this paper, we investigated the correlation between the electrical resistivity and synthesis temperature for aluminum (Al)-modified ZnO. At constant Al doping, the electrical resistivity of ZnO exhibited sharp decrease with increase in sintering temperature due to the increased carrier density resulting from Al3+ substitution on Zn2+ sites. Photoluminescence analysis showed that segregation of Al in secondary phase, ZnAl2O4, promotes Zn2+ vacancy formation and consequently compensates the free electrons that dominate the electrical behavior at relatively low sintering temperature. The mechanism controlling the large change in electrical resistivity of dense ZnO, ranging from insulator (~107 ω cm) to semiconducting regime (~ 0.1 ω cm) has been discussed.
| Original language | English |
|---|---|
| Pages (from-to) | 113-119 |
| Number of pages | 7 |
| Journal | Energy Harvesting and Systems |
| Volume | 1 |
| Issue number | 1-2 |
| DOIs | |
| State | Published - 2014 |
Funding
Authors gratefully acknowledge the financial support provided by NSF/DOE Thermoelectric Partnership program and would like to thank Dr. Hao-Hsiang Liao, Zhenbo Xia and Dr. BoYun Jang for the help with the Van der Pauw method, Impedance and PL measurement, and Dr. Yongke Yan for his helpful suggestions. G. A. Khodaparast would like to thank Doug Wilson for his helps with the lab view programming and acknowledge the support of NSF-REU supplement as part of the NSF-Career Award DMR-0846834.
| Funders | Funder number |
|---|---|
| NSF-CAREER | DMR-0846834 |
| NSF-REU | |
| National Science Foundation | |
| U.S. Department of Energy |
Keywords
- Al-doped ZnO
- carrier density
- defect chemistry
- electrical resistivity
- sintering temperature
- thermoelectric