Interplay of hydrogen treatment and nitrogen doping in ZnO nanoparticles: a first-principles study

Gutjahr, Johann; Sakong, Sung; Kratzer, Peter

doi:10.1088/0957-4484/25/14/145204

Cited by 7 publications

(8 citation statements)

References 18 publications

(28 reference statements)

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“…Both effects will lead to an overall broadening of the ionization edge, as is observed experimentally. This suggestion is also consistent with the theoretical results of Gutjahr et al 44 and Haffad et al 45 , which predicted that incorporation of nitrogen in ZnO is more energetically favorable at (or close to) the surface than in volume regions. This is expected to result in a higher efficiency of N doping in nanostructures with a high surface-to-volume ratio.…”

Section: Resultssupporting

confidence: 92%

“…Based on the lower photo-ionization threshold energy of the N O center in the ZnO NWs as compared with its value in bulk ZnO, the defect is suggested to be located in proximity to the surface. This assumption is consistent with theoretical predictions 44 45 of enhanced N incorporation at or close to the ZnO surface. The revealed doping process is shown to be very efficient leading to a rather high concentration (~2–4 × 10 16 cm −3 ) of unintentional N dopants in the NWs even from the contamination by the source and background gases.…”

Section: Discussionsupporting

confidence: 91%

“…This is expected to result in a higher efficiency of N doping in nanostructures with a high surface-to-volume ratio. Gutjahr et al 44 have explained the decrease in the formation energy by charge transfer between Zn dangling bonds on the surface and the N O impurities. Existence of such dangling bonds on the surface of the studied NWs is indeed confirmed by the observation of signal A in our EPR measurements.…”

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Efficient nitrogen incorporation in ZnO nanowires

Stehr

Chen

Reddy

et al. 2015

Sci Rep

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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.

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Section: Resultssupporting

confidence: 92%

Section: Discussionsupporting

confidence: 91%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Efficient nitrogen incorporation in ZnO nanowires

Stehr

Chen

Reddy

et al. 2015

Sci Rep

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“…Moreover, due to the large surface-to-volume ratio of NWs, defects located at the surface or in its close vicinity become more and more important. Indeed, it was reported that N-related defects near the surface can have different formation energies as well as optical properties [42][43][44].…”

Section: Introductionmentioning

confidence: 99%

Effects of N implantation on defect formation in ZnO nanowires

Stehr

Chen

et al. 2019

Thin Solid Films

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One-dimensional ZnO nanowires are a promising material system for a wide range of optoelectronic and photonic applications. Utilization of ZnO, however, requires high-quality ZnO with reliable n-type and p-type conductivity, with the latter remaining elusive, so far. In this work we report on effects of N doping via ion implantation on defect formation in ZnO nanowires studied by optically detected paramagnetic resonance (ODMR) spectroscopy complemented by photoluminescence spectroscopy. After N implantation, zinc interstitial shallow donors, which are formed as a result of ion implantation, are observed in addition to effective mass type shallow donors. Additionally, ODMR signals related to oxygen vacancies can be observed. Implantation also causes formation of a new nitrogen related defect center, which acts as an acceptor. The present findings are of importance for understanding impacts of different defects and impurities on electronic properties of nanostructured ZnO and achieving ptype conductivity via nitrogen doping.

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“…40,41 Moreover, it was also suggested that the proximity to the surface lowers the formation energies of the N-related acceptors and modifies their photoionization processes. [42][43][44] This may be partly responsible for the promoted p-type conductivity in nanostructured ZnO, 21,28,40,45 though the exact physical mechanism responsible for this effect, as well as the local structure of the incorporated N acceptors, remains unknown.…”

mentioning

confidence: 99%