Effects of varying indium composition on the thermoelectric properties of In x Ga1−x Sb ternary alloys

An Approach to Optimize the Thermoelectric Properties of III–V Ternary InGaSb Crystals by Defect Engineering via Point Defects and Microscale Compositional Segregations

“…The XRD patterns of In x Ga 1– x Sb crystals are shown in Figure . The peaks were broad in nature, which indicated a lattice strain from compositional segregations that was inconsistent with our earlier report . The crystals had a cubic zincblende structure, and the lattice parameters of In 0.85 Ga 0.15 Sb, In 0.90 Ga 0.10 Sb, and In 0.95 Ga 0.05 Sb were calculated, from the high intensity of the peak position, to be 6.4529, 6.4635, and 6.4779 Å, respectively.…”

“…Upon understanding the growth kinetics of the In–Ga–Sb system, we tried to reduce the lattice thermal conductivity by utilizing natural segregation phenomena that occur during the growth process, to reveal the possibilities for this system to be used for TE applications. This was achieved in our previous work, and the thermal conductivity was reduced (above 66%) in the In–Ga–Sb system, successfullyby the change of phonon vibrations from out of phase optical mode to in phase acoustic modeby forming In x Ga 1– x Sb ternary alloys between InSb and GaSb binaries . However, the highest ZT achieved in In 0.8 Ga 0.2 Sb (0.29) is lower than that in binary InSb (0.51) because the segregations affected the electron transport as well, which resulted in a reduced power factor of In–Ga–Sb.…”

“…To utilize the TE conversion process more effectively, much research has been developed by employing various experimental processes and theoretical assumptions to determine the best TE performance in different material systems. − The experimental techniques are focused mostly to reduce the thermal conductivity in a multicomponent system by controlling their lattice thermal conductivity through various phonon scattering processes. It is possible to achieve the high ZT by controlling phonon transport because phonons contribute more than 80% of the total thermal conductivity in many semiconductor materials. − A major issue in controlling the phonon transport is a reduction of the power factor (which results from electron transport) because electron and phonon transport properties are interrelated to each other, which affects the ZT. As the phonons can be considered virtual atomic positions arising from thermal agitation in a crystal lattice, controlling those atomic positions could affect electron transport as well.…”

“…Our research group performed various growth experiments under normal and microgravity conditions to understand the nucleation kinetics of InGaSb ternary alloys. − InGaSb is a III–V ternary alloy whose thermoelectric properties are yet to be understood well. The thermal conductivities of some significant III–V semiconductors such as InSb, InAs, GaSb, GaAs, and AlAs were around 17.5, 30, 36, 45, and 91 W/mK, respectively. , However, the highly efficient TE materials (ZT > 1) possess thermal conductivity less than 1 W/mK. − Thus, the III–V semiconductors have at least one order of higher magnitude of thermal conductivity when compared to other efficient TE materials. Their higher thermal conductivity results from the ease of phonon propagation through their cubic zincblende lattice.…”

Study on crystal growth of In<sub><italic>x</italic></sub>Ga<sub>1−</sub><sub><italic>x</italic></sub>Sb under microgravity

“…In x Ga 1−x Sb晶体可以通过改变In含量进行光电性 能调控, 其晶格常数和吸收波长在6.4794-6.0959 Å和 1.7-6.8 μm范围内控制, 可以制备成高性能的红外探 测器、传感器以及热光伏电池等 [1][2][3] . In的加入不仅可 以调控In x Ga 1−x Sb晶体的带隙, 而且会占据GaSb晶格 结构中的Ga空位(V Ga ), 从而减少其空位缺陷 [4] .…”