AI Article Synopsis
- The study investigates the electronic properties of pure and arsenic-doped silicon nanowires using density functional theory, focusing on how the diameter affects the bandgap.
- For undoped nanowires, the bandgap decreases as the diameter increases, aligning with experimental results, and surface atoms have lesser influence on electronic states compared to those near the center.
- In arsenic-doped nanowires, the position of the dopant significantly impacts the electronic properties, introducing a low velocity band that varies with dopant placement, and leading to valence band edge splitting when the dopant is asymmetrically located.
Article Abstract
The electronic properties of pure and As-doped Si nanowires (NWs) with radii up to 9.53 nm are studied using large scale density functional theory (DFT) calculations. We show that, for the undoped NWs, the DFT bandgap reduces with increasing diameter and converges to its bulk value, a trend in agreement with experimental data. Moreover, we show that the atoms closest to the surface of the nanowire (NW) contribute less to the states near the band edges, when compared with atoms close to the centre; this is shown to be due to differences in Si-Si atomic distances, as well as surface passivation effects. When considering As-doped Si NWs we show that dopant placement within the NW plays an important role in deciding electronic properties. We show that a low velocity band is introduced by As doping, in the gap, but close to the conduction band edge. The curvature of this low velocity band depends on the dopant location, with the curvature reducing when the dopant is placed closer to the center. We also show that asymmetry of dopant location with the NW leads to splitting of the valence band edge.
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| http://dx.doi.org/10.1088/1361-648X/ab4b3c | DOI Listing |
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- The study investigates the electronic properties of pure and arsenic-doped silicon nanowires using density functional theory, focusing on how the diameter affects the bandgap.
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- In arsenic-doped nanowires, the position of the dopant significantly impacts the electronic properties, introducing a low velocity band that varies with dopant placement, and leading to valence band edge splitting when the dopant is asymmetrically located.
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