Low-temperature photoluminescence measurement with a micromachined Joule-Thomson cooler

This study evaluates the effectiveness of micromachined Joule-Thomson (MJT) cooling for photoluminescence (PL) materials. Achieving low temperatures is crucial for enhancing PL performance in semiconductors. However, the commonly used liquid nitrogen (LN2) cryostats require frequent refills, hindering their long-term operation. The MJT cooler offers a potential solution by enabling integration with devices and longer operating time. To validate its effectiveness, this study conducted low-temperature PL measurements using a nitrogen MJT cooler. A MAPbI(3) thin film was used as the characterization sample owing to its clear PL mechanism. The experiment successfully preserved its temperature-dependent PL property, with an observed orthorhombic phase-change phenomenon between 155-165 K. Furthermore, the system demonstrated short cool-down time (<1 h), minimal temperature impact from laser stimulus (<+/- 0.1 K), sample storage stability, and low coolant consumption.