Band gap engineering of the top layer of mica by organized defect formation

Mukherjee, Joy; Dalsaniya, Madhavi H.; Bhowmick, Sudip; Bhowmik, Dipak; Jha, Prafulla K.; Karmakar, Prasanta

doi:10.1016/j.surfin.2022.102283

Cited by 5 publications

(8 citation statements)

References 30 publications

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“…The scaling here, however, incorrectly implies that phyllosilicates in bulk would trend toward being a low E g semiconductor. This apparent finding is in direct opposition to past reports using DFT [ 11f,12b ] and ME. [ 11e,f ] In these studies, E g decreased with layer number due to lattice relaxation.…”

Section: Resultscontrasting

confidence: 99%

“…c) Bandgap ( E g ) for LPE phyllosilicate materials versus mean nanosheet thickness (< t >) in the gray bubble increased with diminishing values of < t > with a power‐law exponent of −0.16 (gray‐dashed line). In the blue and green bubbles, respectively, literary DFT [ 11f,12b ] and ME [ 11e,f ] data also presented power‐law scaling with exponents of 0.16 (blue‐dashed line) and 0.5 (green‐dashed line), respectively. d) Due to the exfoliation mechanism dictated by Figure 3e–g, < L > ∝ <W> resulted in the mean nanosheet area (< A >, i.e., < L > × < W >) expectedly scaling as < A > −1 per Equation .…”

Section: Resultsmentioning

confidence: 99%

“…[ 9 ] Historically, mica is one of the oldest dielectric materials known and possesses a large bandgap ( E g ) of ≈7.85 eV with a dielectric constant between 6 and 9. [ 10 ] However, proof‐of‐concept work via mechanical exfoliation (ME) [ 11 ] and theoretical calculations [ 11f,12 ] have shown that mica presents an E g that is highly dependent on layer number due to an unquantified lattice relaxation effect. [ 12b ] Through the deposition of ME nanosheets onto electrically conductive substrates, current–voltage curves generated via Conductive Atomic Force Microscopy (C‐AFM) were applied to infer information about E g ’s layer dependence.…”

Section: Introductionmentioning

confidence: 99%

“…Through DFT, the E g of a monolayer of mica was predicted to be between ≈3.5 and ≈4.5 eV. [ 11f,12 ] To date, these discrepancies have continued to go unexplained.…”

Section: Introductionmentioning

confidence: 99%

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Exotic Electronic Properties of 2D Nanosheets Isolated from Liquid Phase Exfoliated Phyllosilicate Minerals

Wei,

Roy,

Tripathi

et al. 2023

Advanced Materials

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Spectrally inactive, electrically insulating, and chemically inert are adjectives broadly used to describe phyllosilicate minerals like mica and chlorite. Here, the above is disproved by demonstrating aqueous suspensions of liquid exfoliated nanosheets from five bulk mica types and chlorite schist. Nanosheet quality is confirmed via transmission electron and X‐ray photoelectron spectroscopies, as well as electron diffraction. Through Raman spectroscopy, a previously unreported size‐ and layer‐dependent spectral fingerprint is observed. When analyzing the high‐yield suspensions (≈1 mg mL−1) through UV–vis spectroscopy, all phyllosilicates present bandgap (Eg) narrowing from ≈7 eV in the bulk to ≈4 eV for monolayers. Unusually, the bandgap is inversely proportional to the areal size (A) of the nanosheets, measured via atomic force microscopy. Due to an unrecorded quantum confinement effect, nanosheet electronic properties scale toward semiconducting behavior (bandgap ≈3 eV) as nanosheet area increases. Furthermore, modeling X‐ray diffraction spectra shows that the root cause of the initial bandgap narrowing is lattice relaxation. Finally, with their broad range of isomorphically substituted ions, phyllosilicate nanosheets show remarkable catalytic properties for hydrogen production.

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Section: Resultscontrasting

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…Through DFT, the E g of a monolayer of mica was predicted to be between ≈3.5 and ≈4.5 eV. [ 11f,12 ] To date, these discrepancies have continued to go unexplained.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Exotic Electronic Properties of 2D Nanosheets Isolated from Liquid Phase Exfoliated Phyllosilicate Minerals

Wei,

Roy,

Tripathi

et al. 2023

Advanced Materials

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“…A 5 × 4 × 3 Monkhorst–Pack reciprocal space grid was implemented for Brillouin zone integration . After structural relaxation of the pristine structure, we obtained the lattice parameters at a = 5.19 Å, b = 9.00 Å, c = 20.10 Å, and β = 95.18°, corresponding to other calculations and experiments. − It is important to note that experimental bandgaps are still under debate and vary among 3.60, 5.09, and 7.85 eV . We then aimed to tackled this issue by implementing the modified screened hybrid density functional of Heyd–Scuseria–Ernzerhof (HSE) with the Hartree–Fock exact exchange (α) ratio of 0.37 to circumvent the common underestimation from the conventional Perdew–Burke–Ernzerhof (PBE) .…”

Section: Methodsmentioning

confidence: 99%

Comparative Study of Quantum Emitter Fabrication in Wide Bandgap Materials Using Localized Electron Irradiation

Kumar,

Cholsuk,

Mishuk

et al. 2024

ACS Appl. Opt. Mater.

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Quantum light sources are crucial foundational components for various quantum technology applications. With the rapid development of quantum technology, there has been a growing demand for materials with the capability of hosting quantum emitters. One such material platform uses fluorescent defects in hexagonal boron nitride (hBN) that can host deep sublevels within the bandgap. The localized electron irradiation has shown its effectiveness in generating deep sublevels to induce single emitters in hBN. The question is whether localized (electron beam) irradiation is a reliable tool for creating emitters in other wide bandgap materials and its uniqueness to hBN. Here, we investigate and compare the fabrication of quantum emitters in hBN and exfoliated muscovite mica flakes along with other 3D crystals, such as silicon carbide and gallium nitride, which are known to host quantum emitters. We used our primary fabrication technique of localized electron irradiation using a standard scanning electron microscope. To complement our experimental work, we employed density functional theory simulations to study the atomic structures of defects in mica. While our fabrication technique allows one to create hBN quantum emitters with a high yield and high single photon purity, it is unable to fabricate single emitters in the other solid-state crystals under investigation. This allows us to draw conclusions on the emitter fabrication mechanism in hBN, which could rely on activating pre-existing defects by charge state manipulation. Therefore, we provide an essential step toward the identification of hBN emitters and their formation process.

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Band Gap Engineering and Nanopatterning of Muscovite Mica by Low‐Energy Ion Beams Applicable for Futuristic Microelectronics

Bhowmik,

Mukherjee,

Karmakar

2024

Smart Materials for Science and Engineering

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Band gap engineering of the top layer of mica by organized defect formation

Cited by 5 publications

References 30 publications

Exotic Electronic Properties of 2D Nanosheets Isolated from Liquid Phase Exfoliated Phyllosilicate Minerals

Exotic Electronic Properties of 2D Nanosheets Isolated from Liquid Phase Exfoliated Phyllosilicate Minerals

Comparative Study of Quantum Emitter Fabrication in Wide Bandgap Materials Using Localized Electron Irradiation

Band Gap Engineering and Nanopatterning of Muscovite Mica by Low‐Energy Ion Beams Applicable for Futuristic Microelectronics

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