Realizing Negative Differential Resistance/Switching Phenomena in Zigzag GaN Nanoribbons by Edge Fluorination: A DFT Investigation

Abstract

applications. [10][11][12][13] However, on the other hand, the intrinsic wide bandgap of GaN is a major obstacle in its path for low power electronic devices. To counter this problem, researchers have studied bandgap engineering of 2D GaN via functionalizing its edges with different elements/functional groups as well as suitable dopants. [14][15][16][17][18] Owing to state of the art experimental evolution, nowadays it is possible to synthesize and characterize monolayer of various materials including III-V compound semiconductors. [19][20][21] Recently, Balushi et al., [22] have successfully synthesized graphene encapsulated few layer GaN nanosheet on the SiC substrate. Bhattacharya et al., [23] also synthesized 0.6 nm thick 2D GaN in Na-4 mica channels. In another report, GaN nanosheets were found to sustain at fields as high as 5.8 V nm −1 and 4 V nm −1 for AA'A and ABA stacking respectively which is significantly greater than the breakdown field (0.3-0.5 V nm −1 ) of bulk GaN. [24] Thus it can be concluded that a monolayer of GaN can be used for wider applications in the ambient conditions. However, its wide bandgap still remains a remarkable hurdle for realization of various electronic devices. Recently, halogen functionalization (edge passivation) has been adopted to tailor the electronic properties of zigzag edged graphene nanoribbon. [25] It also results in enhancing the stability of nanoribbons which present them as preferred candidate over edge functionalized ZGNR via H atoms. [25] Motivated from this, in the present work, we studied, the structural and electronic properties of zigzag edged GaN nanoribbons (ZGaNNRs) to reveal its potential applications in the upcoming nanodevices considering various possible combinations of F functionalization. The selection of F atom was expected to result in large charge transfer due to its higher electronegativity and therefore enhancing stability.We have studied the electronic properties of different configurations of ZGaNNRs for different widths (N z = 4-8 dimers). The energy states at the edges of ZGaNNRs significantly alter the band structure and electronic properties of the nanoribbon as compared to energy states in central region. The structural stability for each considered configuration is studied and compared. The NDR effect in 2D material-based devices is observed because of the variation in transmission coefficient and difference of the Fermi functions affected by density of states (DOS).Gallium nitride (GaN) is a commonly used material for the high power electronic devices. Its 2D analog (layered GaN) can be a promising material in low power applications due to its flexible bandgap. This study investigates the structural stability, electronic and transport properties of zigzag edged GaN nanoribbons (ZGaNNRs), considering various edge passivations to gauge its potential for beyond silicon electronic devices. Present density functional theory based calculations reveal that metallic/semiconducting nature can be obtained in ZGaNNRs via controlled edge fluorin...

Hydrogenated cove-edge aluminum nitride nanoribbons for ultrascaled resonant tunneling diode applications: a computational DFT study

“…The E b of the H-AlN-Cove are found to be lower negative as listed in table 2 while the Cove-AlN-H has more negative E b . The bond length elongation at the Alrich edge improves the stability of Cove-AlN-H which is in accordance with the previous study [37]. Owing to the redistribution of charge density at the saturated Al edge, H-AlN-Cove followed by H-AlN-H shows lower negative E b .…”

“…Owing to the wide energy bandgap of the AlNNRs, we have considered a wide voltage bias (V b ) range from 0 to 1.6 V. This V b range is in good agreement with the previous study [37]. The computed I-V characteristics of the investigated pristine and cove-edge AlNNNR devices are shown in figure 6.…”

Negative Pulse and Compliance Current Dependent Negative Differential Resistance in ZnO/Nb:SrTiO3 Heterojunctions

“…[1][2][3][4][5] In addition to double-quantum wells, superlattices, molecules, and 1D systems, NDR has also been widely found in oxides with bipolar resistance switching (RS), which attracts much attention for multifunctional electronic devices and neuromorphic computing. [6][7][8][9][10][11] The NDR feature has been found to be strongly dependent on temperature, [7,10] moisture, [8] bias voltage, [12][13][14] air exposure, [15] metal ion implantation, [16] edge fluorination, [17] ferroelectric polarization switching, [18,19] light irradiation, [20] and magnetic field. [21] In our previous reports, temperature-and positive pulse-dependent NDR accompanying RS was studied.…”

Modulating the properties of multi-functional molecular devices consisting of zigzag gallium nitride nanoribbons by different magnetic orderings: a first-principles study

“…Therefore, many researchers have studied the band gap characteristics of GaN nanomaterials via functionalizing the edge structures with suitable dopants, such as hydrogen, fluorine, chlorine and other terminal groups. 2,20,21 As we know that the H-passivated and bare armchair GaNNRs can be classified as nonmagnetic semiconductors, the band gap gradually decreases with the increase of the width of nanoribbons. The bare ZGaNNRs are ferromagnetic, and their spin-polarized ratio is 100% at the Fermi energy while their conductivity is dominated by the metallic singlespin state.…”

“…And Balushi et al experimentally found that the planar structure of GaN exhibits an indirect energy gap of 4.12 eV, and the buckled structure maintains a direct gap of 5.28 eV. 17 Inge et al claimed that the F passivated ZGaNNR model exhibits sNDR and switching characteristics with a sufficiently large peak to valley current ratio/ threshold voltage on the order of 10 2 -10 14 /2.8-3.6 V. 20 Moreover, the results of electronic behaviors of ZGaNNRs have shown that one edge hydrogenated ZGaNNRs lead to 100% spin polarization. 2 Although the electronic structure of edge hydrogenated ZGaNNRs has been reported frequently, their spin transport behaviors are rarely studied.…”