Micromachined Joule-Thomson cooling for long-time and precise thermal management.

Abstract

Efficient thermal management is essential for low-temperature optoelectronic devices. Traditional liquid nitrogen (LN2) cooling presents challenges such as frequent replenishment needs and limited operational duration. This study introduces micromachined Joule-Thomson (MJT) cooling as a superior alternative for temperature regulation in optoelectronic devices. We evaluated the thermal and optical performance of MJT cooling for a CdSe/ZnS quantum dot (QD) sample within a temperature range of 120-300K. Thermal analysis showed that with a single 50 l nitrogen refill, the MJT system can operate continuously for over one week, surpassing the LN2 system by 11 times. The temperature stability was affected little by laser irradiation, with a <0.2K rise at 5 mW of laser power. In addition, the MJT cooling led to an average blueshift of 1-3meV in the emission peak of QDs and 0.3-2.3meV reduced spectral broadening compared to LN2, attributed to a smaller sample-to-cold-stage temperature gap of about 8-9K in the MJT setup. The standard deviations of peak energy and FWHM are in the order of E - 1meV magnitude, demonstrating a comparable thermal uniformity compared to LN2. The vibration spectra obtained for both vertical and horizontal directions reveal the superior low-vibration characteristics of MJT cooling. These findings validate MJT cooling as a superior and reliable strategy for the thermal management of optoelectronics, ensuring prolonged operational durations, reliable temperature stability, enhanced temperature precision, high thermal homogeneity, and low vibrations.