The effect of vacancies and the substitution of p-block atoms on single-layer buckled germanium selenide

Ersan, Fatih; Arkin, Handan; Aktürk, Ethem

doi:10.1039/c7ra05099b

Cited by 26 publications

(10 citation statements)

References 54 publications

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“…DFT calculations have predicted that the Se vacancy in a neutral charge state can result in mid-gap states, consistent with the lowered onset of absorption observed experimentally [28]. Additionally, for orthorhombic monolayer GeSe, DFTpredicted formation energies suggest that the Se vacancy is preferred to a Ge vacancy [29], while in the buckled hexagonal structure, DFT-based studies predict that Ge is the preferred vacancy [30].…”

Section: Arxiv:200510102v1 [Cond-matmtrl-sci] 20 May 2020supporting

confidence: 55%

Localized excitons in defective monolayer germanium selenide

Cohen

Lewis

Huang

et al. 2020

Phys. Rev. Materials

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Germanium Selenide (GeSe) is a van der Waals-bonded layered material with promising optoelectronic properties, which has been experimentally synthesized for 2D semiconductor applications. In the monolayer, due to reduced dimensionality and, thus, screening environment, perturbations such as the presence of defects have a significant impact on its properties. We apply density functional theory and many-body perturbation theory to understand the electronic and optical properties of GeSe containing a single selenium vacancy in the −2 charge state. We predict that the vacancy results in mid-gap "trap states" that strongly localize the electron and hole density and lead to sharp, low-energy optical absorption peaks below the predicted pristine optical gap. Analysis of the exciton wavefunction reveals that the 2D Wannier-Mott exciton of the pristine monolayer is highly localized around the defect, reducing its Bohr radius by a factor of four and producing a dipole moment along the out-of-plane axis due to the defect-induced symmetry breaking. Overall, these results suggest that the vacancy is a strong perturbation to the system, demonstrating the importance of considering defects in the context of material design.

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Section: Arxiv:200510102v1 [Cond-matmtrl-sci] 20 May 2020supporting

confidence: 55%

Localized excitons in defective monolayer germanium selenide

Cohen

Lewis

Huang

et al. 2020

Phys. Rev. Materials

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“…4(e) illustrates the M – H curves of the samples at room temperature with H applied in plane. Interestingly, pure GeSe flakes exhibit a weak FM with a small saturation magnetization ( M S ∼ 2.0 × 10 –3 emu cm −3 ), probably induced by intrinsic V Ge s 14 or the dangling bonds in the samples. 40 The GeMnSe samples show distinct hysteresis curves, indicating robust ferromagnetic ordering.…”

Section: Resultsmentioning

confidence: 99%

Structure-dependent high-T_C ferromagnetism in Mn-doped GeSe

Zhang

et al. 2022

Nanoscale

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“…73 GeSe normally exhibits p-type conductivity due to the native Ge vacancy. 74 The best measured majority mobility is 128.7 cm 2 V À1 s À1 , higher than that of CH 3 NH 3 PbI 3 single crystals. Kim Our group also systematically investigated the electrical properties of polycrystalline GeSe thin film prepared by our rapid thermal sublimation method (this method will be discussed in detail in Section 3).…”

Section: Electrical Propertiesmentioning

confidence: 87%