Da Silva, JLF;
STRUCTURAL, ELECTRONIC, AND OPTICAL PROPERTIES OF THE IN2O3(ZNO)(N) SYSTEM.
Presented at: 34th IEEE Photovoltaic Specialists Conference, Philadelphia, PA.
We studied the structural, electronic, and optical properties of the In2O3(ZnO)(n) system by a combination of high-resolution electron microscopy, image simulation, and density-functional theory calculation. We found that the In2O3(ZnO)(n) system has a polytypoid structure that consists of wurtzite InZnnOn., slabs separated by single In-O octahedral layers. These octahedral layers are inversion domain boundaries and satisfy the electronic octet rule. The InZnnOn+1 slabs contain another type of boundary that inverts the polarities again. This boundary prefers a zigzag modulated structure and also obeys the electronic octet rule. We also found that the red-shift in optical transitions for the In2O3(ZnO)(n) system as compared to individual In2O3 and ZnO systems is because the symmetry-forbidden band-edge transitions in In2O3 are overcome by the formation of superlattices, with ZnO contributions to the top of the valence band. We further found that increasing n results in an enhanced valence-band maximum in the ZnO region, while the conduction-band minimum becomes more localized on the InO2 layers, which introduces confinement to electron carriers. Such enhanced localization explains why Zn-rich compounds (higher n) exhibit lower conductivity.
|Type:||Conference item (UNSPECIFIED)|
|Title:||STRUCTURAL, ELECTRONIC, AND OPTICAL PROPERTIES OF THE IN2O3(ZNO)(N) SYSTEM|
|Event:||34th IEEE Photovoltaic Specialists Conference|
|Dates:||07 June 2009 - 12 June 2009|
|UCL classification:||UCL > School of BEAMS > Faculty of Maths and Physical Sciences
UCL > School of BEAMS > Faculty of Maths and Physical Sciences > Chemistry
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