Strain effects on work functions of pristine and potassium-decorated carbon nanotubes

“…Strain has long been used to tune electronic properties of semiconductors [11,12]. As a practical issue, strain is almost inevitable in fabricated monolayer nanostructures, manifesting as the formation of ridges and buckling [13,14]. A more interesting case comes from intentionally introduced and controlled strains, though.…”

Section: /V·smentioning

confidence: 99%

Strain-engineered direct-indirect band gap transition and its mechanism in two-dimensional phosphorene

2014

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Recently fabricated two-dimensional phosphorene crystal structures have demonstrated great potential in applications of electronics. In this paper, strain effect on the electronic band structure of phosphorene was studied using first-principles methods including density functional theory (DFT) and hybrid functionals. It was found that phosphorene can withstand a tensile stress and strain up to 10 N/m and 30%, respectively. The band gap of phosphorene experiences a direct-indirect-direct transition when axial strain is applied. A moderate −2% compression in the zigzag direction can trigger this gap transition. With sufficient expansion (+11.3%) or compression (−10.2% strains), the gap can be tuned from indirect to direct again. Five strain zones with distinct electronic band structure were identified, and the critical strains for the zone boundaries were determined. Although the DFT method is known to underestimate band gap of semiconductors, it was proven to correctly predict the strain effect on the electronic properties with validation from a hybrid functional method in this work. The origin of the gap transition was revealed, and a general mechanism was developed to explain energy shifts with strain according to the bond nature of near-band-edge electronic orbitals. Effective masses of carriers in the armchair direction are an order of magnitude smaller than that of the zigzag axis, indicating that the armchair direction is favored for carrier transport. In addition, the effective masses can be dramatically tuned by strain, in which its sharp jump/drop occurs at the zone boundaries of the direct-indirect gap transition.

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“…the work function of the deformed cnts can be approximated by curve fitting the calculated values [45], [46] ,…”

Section: Contact-tunneling Effectmentioning

confidence: 99%

Piezoresistive Strain Sensors Based on Carbon Nanotube Networks: Contemporary approaches related to electrical conductivity

Zhu

2015

IEEE Nanotechnology Mag.

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june 2015 | IEEE nanotEchnology magazInE | 11 S zhEng h. zhu Piezoresistive Strain Sensors Based on Carbon Nanotube Networks Treated CNT/SPU [84] Pristine CNT/PP [85] Pristine CNT/PA12 [86] Pristine CNT/TPU [87] Pristine CNT/IPPAM [88] Pristine CNT/PP12 [89] Pristine CNT/PBT [89] Pristine CNT/PC [89] Pristine CNT/PEEk [89] Pristine CNT/LDPE [89]FIGURE 3 A comparison of electrical conductivity of CNT/polymer nanocomposites with treated and pristine Baytubes, C150P [13].

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Strain effects on work functions of pristine and potassium-decorated carbon nanotubes

Cited by 33 publications

References 33 publications

On the mechanism of piezoresistivity of carbon nanotube polymer composites

On the mechanism of piezoresistivity of carbon nanotube polymer composites

Strain-engineered direct-indirect band gap transition and its mechanism in two-dimensional phosphorene

Piezoresistive Strain Sensors Based on Carbon Nanotube Networks: Contemporary approaches related to electrical conductivity

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