Orientation- and passivation-dependent stability and electronic properties of α-Si₃N₄nanobelts

Abstract

The energetic stability and electronic properties of unpassivated, hydrogen (-H) and hydroxyl (-OH) passivated α-Si3N4 nanobelts orientating along the [101], [210], [011], [100], [001], and [110] directions are investigated by first-principles calculations. Calculations show that the energetic stabilities of α-Si3N4 nanobelts depend weakly upon orientations of nanobelts, but sensitively on passivation treatments. The most stable nanobelt is the OH cluster partially passivated α-Si3N4, followed by the H atom fully passivated and the unpassivated systems. All the unpassivated nanobelts show metallic characteristics due to the presence of dangling bonds of surficial atoms in nanobelts, while all the passivated nanobelts exhibit semiconducting characteristics. The valence band maximum (VBM) and the conduction band minimum (CBM) mainly originate from the surface N-2p and Si-3p states, respectively. For α-Si3N4 nanobelts orientating along [101], [210], [011] and [110] directions, the OH passivated systems exhibit a much smaller band gap than the H passivated systems, while the [100] and [001] orientated nanobelts exhibit the opposite band-gap properties.

Investigation of photoelectrical properties of α-Si3N4nanobelts with surface modifications using first-principles calculations

“…The structure of bulk a-Si 3 N 4 was optimized and its electronic properties, including the band structure and densities of states (DOS), were calculated. The calculated lattice parameters and electronic properties were presented in our previous study, 50 which are in good agreement with the experimental and other calculated results. [55][56][57][58] In this work, the electron and hole effective masses and the complex dielectric function e(o) of bulk a-Si 3 N 4 were calculated to further check the validity of the above computational methods.…”

“…In our previous study, 50 the effects of surface modifications and growth orientations of a-Si 3 N 4 nanobelts on the energetic stability and electronic properties were investigated via firstprinciples calculations. The results show that OH modification can improve the stability and increase or decrease the band gap compared with H modification.…”

2D Materials Based on Main Group Element Compounds: Phases, Synthesis, Characterization, and Applications

“…Herein, the orientations and surface passivation determined the stability of the α‐Si 3 N 4 nanobelt as well as its electronic properties such as band characteristics (direct, indirect, and metallic). [ 359 ]…”

Facile synthesis of α‐Si3N4 nanoneedles and their photoluminescence properties

“…One‐dimensional (1D) nanomaterials (nanotubes, nanowires, nanobelts, nanoneedles) have drawn great attention in recent decades. Given their high surface‐to‐volume ratio, 1D nanomaterials have extensive potential to be applied in optical materials, ceramics, electronics, and biomaterials etc .…”