New Twin Structures in GaN Nanowires

Dai, Sheng; Zhao, Jiong; He, Mo Rigen; Wu, Hao; Xie, Lin; Zhu, Jing

doi:10.1021/jp403263u

Cited by 10 publications

(18 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The measured angle between two sets of (0001) plane is about 124°, in good agreement with that of (101 ത 1) twin. Therefore, this kind of TBs is the most common type and always observed in wurtzite structure nanowire, such as GaN 36 , ZnO 37 and so on. Figure 2f and 2g show the bicrystalline GaN nanowire taken along [12 ത 10] zone axis.…”

Section: Resultsmentioning

confidence: 99%

“…Besides the above (101 ത 3) and (101 ത 1) twin structures, we also found a third kind of twin structure in the undoped GaN nanowires. 36 Once twin nucleuses are generated, GaN bicrystals will grow up due to high energy state of the TBs, forming bicrystalline GaN nanowires. One can see that the coincident spot representing the TB is (202 ത 1) plane, as indexed in the SAED pattern ( Figure 2g).…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Zn-dopant dependent defect evolution in GaN nanowires

et al. 2015

View full text Add to dashboard Cite

Zn doped GaN nanowires with different doping levels (0, <1 at%, and 3-5 at%) have been synthesized through a chemical vapor deposition (CVD) process. The effect of Zn doping on the defect evolution, including stacking fault, dislocation, twin boundary and phase boundary, has been systematically investigated by transmission electron microscopy and first-principles calculations. Undoped GaN nanowires show a hexagonal wurtzite (WZ) structure with good crystallinity. Several kinds of twin boundaries, including (101¯3), (101¯1) and (202¯1), as well as Type I stacking faults (…ABABCBCB…), are observed in the nanowires. The increasing Zn doping level (<1 at%) induces the formation of screw dislocations featuring a predominant screw component along the radial direction of the GaN nanowires. At high Zn doping level (3-5 at%), meta-stable cubic zinc blende (ZB) domains are generated in the WZ GaN nanowires. The WZ/ZB phase boundary (…ABABACBA…) can be identified as Type II stacking faults. The density of stacking faults (both Type I and Type II) increases with increasing the Zn doping levels, which in turn leads to a rough-surface morphology in the GaN nanowires. First-principles calculations reveal that Zn doping will reduce the formation energy of both Type I and Type II stacking faults, favoring their nucleation in GaN nanowires. An understanding of the effect of Zn doping on the defect evolution provides an important method to control the microstructure and the electrical properties of p-type GaN nanowires.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Zn-dopant dependent defect evolution in GaN nanowires

et al. 2015

View full text Add to dashboard Cite

show abstract

“…26 Among the as-synthesized products, high resolution transmission electron microscopy (HRTEM) was used to find two distinct structures of GaN NWs, single crystalline (SC) NWs and obtuse-angle twin (OT) NWs. 26 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 For SC GaN NWs, the HRTEM image along [010] zone axis (Figure 1e) clearly demonstrates the single crystallinity.…”

mentioning

confidence: 99%

“…In fact, it is an isosceles triangle with a 63.2° apex while the base is parallel to (001) planes. 17,18,26 The developed facets at two base angles can also be observed and were attributed to fluctuations in reaction conditions that affected the stability of the growth of a certain plane. 17,26 As illustrated in the model of this cross section shape (Figure 1b), h and b are the height and base of the isosceles triangle, respectively.…”

mentioning

confidence: 99%

“…Either part on both sides of the TB grows along the <423> direction and the atomic profile of the {304} TB can be referred to our former work. 26 Here, the dumbbell-shape cross section could be treated mathematically as the model in Figure 1g. It could be described as two circles passing through the center of each other with the radius R (See Supplementary Materials 1for more details).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Elastic Properties of GaN Nanowires: Revealing the Influence of Planar Defects on Young’s Modulus at Nanoscale

Dai,

Zhao,

et al. 2014

Nano Lett.

Self Cite

View full text Add to dashboard Cite

The elastic properties of gallium nitride (GaN) nanowires with different structures were investigated by in situ electron microscopy in this work. The electric-field-induced resonance method was utilized to reveal that the single crystalline GaN nanowires, along [120] direction, had the similar Young's modulus as the bulk value at the diameter ranging 92-110 nm. Meanwhile, the elastic behavior of the obtuse-angle twin (OT) GaN nanowires was disclosed both by the in situ SEM resonance technique and in situ transmission electron microscopy tensile test for the first time. Our results showed that the average Young's modulus of these OT nanowires was greatly decreased to about 66 GPa and indicated no size dependence at the diameter ranging 98-171 nm. A quantitative explanation for this phenomenon is proposed based on the rules of mixtures in classical mechanics. It is revealed that the elastic modulus of one-dimensional nanomaterials is dependent on the relative orientations and the volume fractions of the planar defects.

show abstract

Morphology‐Controlled Synthesis of CuO, CuO Rod/MWW Composite for Advanced Oxidation of Indole and Benzothiophene

et al. 2019

View full text Add to dashboard Cite

Various morphologies of copper (II) oxide (CuO) such as dandelion, sea anemone, walnut, leaf, dendrite, rod, fiber, feather, and flake were synthesized and characterized by different methods. The oxidation of indole (IND) and benzothiophene (BT) in mild conditions was studied by various morphologies of CuO. Walnut with the lowest surface area 7.928 (m2g−1) and rod with a high surface area 41.237 (m2g−1) had efficiencies of 5.93% and 91.44% for IND and 0.53% and 88.29% for BT at 4 h, respectively. Zeolite MWW was synthesized by microwave and hydrothermal method on which CuO rod was loaded via wet impregnation method. The results indicated that CuO rod/MWW composite considerably outperformed CuO rod. The oxidations of IND and BT by CuO rod/MWW composite for 75 min was 99.99 and 97.67%, respectively. Based on the results across all experiments, the oxidation of the IND was higher than that of BT. CuO rod/MWW composite was shown to be an efficient catalyst for oxidation of nitrogen and sulfur heterocycles.

show abstract

New Twin Structures in GaN Nanowires

Cited by 10 publications

References 50 publications

Zn-dopant dependent defect evolution in GaN nanowires

Zn-dopant dependent defect evolution in GaN nanowires

Elastic Properties of GaN Nanowires: Revealing the Influence of Planar Defects on Young’s Modulus at Nanoscale

Morphology‐Controlled Synthesis of CuO, CuO Rod/MWW Composite for Advanced Oxidation of Indole and Benzothiophene

Contact Info

Product

Resources

About