Utilizing the transverse thermoelectric effect of 4H-SiC for infrared laser detectors across a power range spanning from milliwatts to hundreds of watts

Abstract

In this work, infrared (IR) laser detectors have been designed and fabricated based on the transverse thermoelectric effect of c axis tilted n-type 4H-SiC homoepitaxial materials. The power measurement range of such detectors has been checked by a 940 nm laser with low power (31–186 mW) and a 1080 nm laser with high power (25–150 W). It is shown that the detectors can operate in a wide range of laser powers, with a minimum power threshold of 31 mW and a maximum detection capability of 150 W. The sensitivity in such a wide power range is almost a constant of around 7.53 μV/W, within the consideration of the absorption coefficient difference between 940 and 1080 nm. This also indicates that such detectors can work in a wide range of IR wavelengths by normalizing the absorption coefficient. In addition, these 4H-SiC detectors demonstrate remarkable stability under thermal cycling tests between cryogenic (−197 °C) and extreme high-temperature (1000 °C) conditions. These findings may provide an effective solution for fabricating IR laser detectors capable of operating across 5 orders of magnitude (milliwatts to hundreds of watts) while withstanding harsh environments.