GaN Monolithic Optopairs for Rapid and High-Resolution Temperature Measurements

This article presents the fabrication and characterization of a gallium nitride (GaN)-based optopair for the temperature measurement. The monolithic device comprises a pair of indium gallium nitride (InGaN)/GaN multiquantum well diodes, enabling both light emission and detection functions. The device exhibits a monotonic increase in photocurrent response with increasing temperature, attributed to the increased spectral overlap between the emission and absorption. The developed device with a size of 1.1 x 1.3 mm (2) is capable of responding to changes in temperature range from 26.5 degrees C to 150 degrees C. With the advantages of fast response of less than 0.5 s, high resolution of 0.024 degrees C, and compact structure, the proposed chip-scale design shows great potential in the field of high-precision, real-time temperature measurement.