First-principles calculations for the structural and electronic properties of GaAs1−xPx nanowires

Abstract

Structural stability and electronic properties of GaAs 1Àx P x (0:0 x 1:0) nanowires (NWs) in zinc-blende (ZB) ($ 5 diameter $ 21 Å) and wurtzite (WZ) ($ 5 diameter $ 29 Å) phases are investigated by¯rst-principles calculations based on density functional theory (DFT). GaAs (x ¼ 0:0) and GaP (x ¼ 1:0) compound NWs in WZ phase are found energetically more stable than in ZB structural ones. In the case of GaAs 1Àx P x alloy NWs, the energetically favorable phase is found size and composition dependent. All the presented NWs have semiconductor characteristics. The quantum size e®ect is clearly demonstrated for all GaAs 1Àx P x (0:0 x 1:0) NWs. The band gaps of ZB and WZ structural GaAs compound NWs with $ 10 diameter $ 21 Å and $ 5 diameter $ 29 Å, respectively are enlarged by the addition of concentrations of phosphorus for obtaining GaAs 1Àx P x NWs proportional to the x values around 0.25, 0.50 and 0.75.

Advanced Thermoelectric Design: From Materials and Structures to Devices

“…(g) Calculated bandgap of GaAs 1– x P x as a function of diameter. Reprinted with permission from ref . Copyright 2016 World Scientific.…”

“…498 The I−V curves were acquired by scanning tunneling spectroscopy under an ultrahigh vacuum environment, and the bias voltage is from −2 to 2 V. It can be seen that with decreasing diameter, higher current can be achieved, indicating that the strengthening of the quantum confinement effect can benefit the electrical transport performance of QWs. Figure 22g shows the bandgap, calculated by first-principles DFT methods, of GaAs 1−x P x as a function of diameter with different x values; 502 the inset shows a typical crystal structure of GaAs. With increasing the diameter, the bandgap can be significantly reduced due to quantum confinement effect, and with increasing x, a higher bandgap can be achieved, indicating that compositional design can alter the electrical transport performance of QWs.…”

A theoretical investigation on equilibrium magnetic properties in nanowire arrays

“…In addition to experimental studies, there are a significant number of theoretical studies in the literature. Many of these theoretical studies involving magnetic nanowires use density functional theory (DFT) calculations, as cited in references [24][25][26][27][28]. DFT calculations provide insight into the behavior and properties of magnetic nanowires.…”