Efficient nitrogen incorporation in ZnO nanowires

Abstract

One-dimensional ZnO nanowires (NWs) are a promising materials system for a variety of applications. Utilization of ZnO, however, requires a good understanding and control of material properties that are largely affected by intrinsic defects and contaminants. In this work we provide experimental evidence for unintentional incorporation of nitrogen in ZnO NWs grown by rapid thermal chemical vapor deposition, from electron paramagnetic resonance spectroscopy. The incorporated nitrogen atoms are concluded to mainly reside at oxygen sites (NO). The NO centers are suggested to be located in proximity to the NW surface, based on their reduced optical ionization energy as compared with that in bulk. This implies a lower defect formation energy at the NW surface as compared with its bulk value, consistent with theoretical predictions. The revealed facilitated incorporation of nitrogen in ZnO nanostructures may be advantageous for realizing p-type conducting ZnO via N doping. The awareness of this process can also help to prevent such unintentional doping in structures with desired n-type conductivity.

Exploring Surface Effects in Co Doped ZnO Nanowires With Hybrid‐Density Functional Theory

“…Later on we have investigated the incorporation of N in ZnO nanowires and showed the effect of hydrogen passivation on N incorporation. Our results have suggested that N should sit close to surface sites, which has been later confirmed experimentally . We show here that by passivating the nanowire surfaces with hydrogen, Co have a lower formation energy than when it is incorporated in the bulk (for both PBE and HSE functionals), as shown in Table .…”

Acceptor-modulated optical enhancements and band-gap narrowing in ZnO thin films

“…44 But via an increase in the flow ratio of N 2 , double nitrogen atoms occupy the single oxygen site which results to form double shallow level instead of single deep acceptor. [54][55][56] Optical conductivity of a material is another prime factor which offers vigorous information about band structure of any material. More precisely, it describes the electronic states distribution when optical radiation strikes the surface of the films.…”

Heparin‐Mediated Growth of Self‐Organized ZnO Quasi‐Microspheres with Twinned Donut‐Like Hierarchical Structures

“…The HRTEM image in Figure c, d was taken on the ultrathin edges of the microsphere rim, which can gave insights into crystal orientation of the nanosheets. The lattice fringes, with an interplanar spacing of 0.261 nm, corresponded to the (002) planes of the ZnO hexagonal structure, suggesting that the ZnO nanosheets stacked together along the polar c‐axis . Moreover, all these microparticles remained its integrity even after long‐time ultrasonic dispersion treatment, suggesting their sufficient stable hierarchical mosaics via the oriented attachment and strong polar‐ploar interaction induced by the intrinsic crystallographically polar surfaces…”