Phase diagrams and optical properties of phosphide, arsenide, and antimonide binary and ternary III-V nanoalloys

We report a theoretical investigation, at the nanoscale, free of any adjustable parameters, concerning the size, shape, composition, and segregation effects on the melting temperature and energy band gap of zinc-blende III-V semiconductors. The corresponding nanophase diagram is established. From it, the composition and segregation effects on the energy band gap of the ternary semiconducting nanoalloy are deduced. Moreover, the liquid surface energies for AlP, GaP, AlAs, and AlSb have been calculated ($0.566\pm 0.060$, $0.510\pm 0.060$, $0.506\pm 0.060\text{J}/{\text{m}}^2$, and $0.441\pm 0.060\text{J}/{\text{m}}^2$, respectively). The information obtained in this study can be used to tune the thermo-optical properties of III-V nanomaterials in nano-optoelectronics.

Figure 1

(Color online) Surface energy in the liquid state versus the surface energy in the solid state for the III-V semiconductors.

Figure 2

(Color online) Surface energy in the liquid state versus the molar mass of the III-V semiconductors.

Figure 3

(Color online) (a) The melting temperature [calculated with Eq. (1)] and the energy band gap [calculated with Eq. (2)] versus the radius (L) of spherical nanoparticle of AlP, GaP, and InP. The solid lines and dashed and dotted lines correspond to AlP, GaP, and InP, respectively. The colors are used to distinguish the melting temperature in black from the energy band gap in blue. (b) The melting temperature [calculated with Eq. (1)] and the energy band gap [calculated with Eq. (2)] versus the radius (L) of spherical nanoparticle of AlAs, GaAs, and InAs. The solid lines and dashed and dotted lines correspond to AlAs, GaAs, and InAs, respectively. The colors are used to distinguish the melting temperature in black from the energy band gap in blue. (c) The melting temperature [calculated with Eq. (1)] and the energy band gap [calculated with Eq. (2)] versus the radius (L) of spherical nanoparticle of AlSb, GaSb, and InSb. The solid lines, dashed and dotted lines correspond to AlSb, GaSb, and InSb, respectively. The colors are used to distinguish the melting temperature in black from the energy band gap in blue.

Figure 4

(Color online) Phase diagram of III-V miscible semiconductors. The solidus (red) and liquidus (black) curves are indicated for the bulk material (thick lines) and the spherical nanomaterial (thin lines) with a radius equal to 2 nm and without segregation [calculated with Eq. (5)].

Figure 5

(Color online) Phase diagram of the InAsSb alloy considering the segregation effect. To plot the graph, we take $\Delta H_{\text{sub}}\approx \Delta H_{\text{vap}}=5\text{kT}$. The solid lines correspond to the nanocore, and the dashed lines correspond to the nanosurface. The solidus and liquidus curves are indicated in red and black, respectively.

Figure 6

Direct energy band gap versus the composition of the alloy (a) InAsP, (b) InAsSb, (c) GaAsSb, (d) InGaSb, and (e) InGaAs. The thick line indicates the bulk behavior, and the thin one indicates the spherical nanomaterial behavior with a radius equal to 2 nm and without segregation.