辐射换热对悬空微器件温度的影响

Effect of Thermal Radiation on Temperature of Microfabricated Suspended Devices

基于悬空微器件法的一维纳米结构热物性测量技术在纳尺度传热研究中得到了广泛的应用。为了研究辐射换热给这类实验测试带来的误差,本文在20~360 K温度范围内测试了低温恒温器中遮热罩的个数对悬空微器件热源/热沉和基底温度的影响。研究结果表明：在没有加热电流的情况下,使用三层遮热罩时,热源/热沉温度和基底温度的差异可以忽略;采用两层遮热罩时,热源/热沉温度同基底温度最多差0.4 K;只使用一层遮热罩时,辐射换热使得360 K时热源/热沉温度比基底温度低11.8 K。因此,为了降低辐射换热对实验结果的影响,低温恒温器中至少应该使用2个遮热罩。

Here, we experimentally addressed the thermal shielding of the suspended one-dimensional, micro-fabri- cated nano-devices in ambient environment with the lab-built measurement setup in a cryostat. The effect of the number of the thermal radiation shield on the temperature difference between the substrate and the micro-fabricated heater and heat- sink, was investigated in 20 - 360 K range. The results show that the number of shield strongly affects the temperature dif- ference between the substrate and heater/heat-sink. To be specific, with three thermal shields but without resistive heat- ing, the temperature difference was negligible;with two shields, the largest temperature difference was 0.4 K;and with a single shield and at 360 K, the temperature of the heater/heat-sink was 11.8 K lower than that of the substrate, and that could be a problem. We suggest that to reduce the impact of radiation, at least two shields should be used in characteriza- tion of the suspended nanostructures device.