The potential of Er-doped Al x In 0:1 Ga 0:9Àx N quaternary alloys as high-temperature thermoelectric (TE) materials has been explored. It was found that the incorporation of Er significantly decreased the thermal conductivity () of Al x In 0:1 Ga 0:9Àx N alloys. The temperature-dependent TE properties were measured up to 1055 K for an Er and Si co-doped n-type Al 0:1 In 0:1 Ga 0:8 N alloy. The figure of merit (ZT ) showed a linear increase with temperature and a value of about 0.3 at 1055 K was estimated. The ability to survive such high temperature with reasonable TE properties suggests that low-In-content Er and Si-doped AlInGaN alloys are potential candidate of high-temperature TE materials.

Thermoelectric (TE) properties of erbium-silicon co-doped InxGa1-xN alloys (InxGa1-xN: Er + Si, 0≤x≤0.14), grown by metal organic chemical vapor deposition, have been investigated. It was found that doping of InGaN alloys with Er atoms of concentration, N[Er] larger than 5x1019 cm-3, has substantially reduced the thermal conductivity, κ, in low In content InGaN alloys. It was observed that κ decreases as N[Er] increases in Si co-doped In0.10Ga0.90N alloys. A room temperature ZT value of ~0.05 was obtained in In0.14Ga0.86N: Er + Si, which is much higher than that obtained in un-doped InGaN with similar In content. Since low In content InGaN is stable at high temperatures, these Er+Si co-doped InGaN alloys could be promising TE materials for high temperature applications.