Improvements in the Low-Frequency Characteristic and Sensitivity of a Thin-Film Multijunction Thermal Converter in Vacuum

摘要

We have improved the ac-dc transfer differences and enhanced the sensitivity in our thin-film multijunction thermal converters (TFMJTCs) in vacuum. The ac-dc transfer differences of the TFMJTCs are less than 1 V/V down to 1 Hz and 10 V/V down to 0.2 Hz owing to the increased thermal time constant. The measured output voltage exceeds 120 mV at Pa owing to the reduction of heat conduction to the air. The sensitivity of the device, defined as the ratio of the output voltage to the input power, is 2.4 V/W, which is approximately three times larger than that measured at ambient pressure. Numerical simulations of the heat transfer of our TFMJTC explain the experimental results well.