基于粗糙介质薄膜的高性能MEMS红外光源研究

Research on MEMSInfrared Emitter with High Performance Based on a Textured Dielectric Film

目前,工业领域对于气体监测的需求日益增长,在各种气体传感器中,红外传感器由于其高精度、高选择性的优势得到了广泛开发应用。红外光源是红外传感器中的关键元件,其发射率决定了传感器的性能,传统的发射率提高方法主要为制作表面微结构和添加高吸收率材料等。然而,这些方法会导致成本增加、制造复杂度提高。我们提出了一种新型MEMS红外光源,使用粗糙介质薄膜增强红外吸收并降低热传导来提高发射率。粗糙介质薄膜结构通过简单的硬模工艺制作,该方法成本低并与传统的红外光源制造兼容,制造的红外光源在2-20μm内可以达到99%以上的发射率。该红外光源的辐射区面积为1.4 mm×1.5 mm,在425℃的工作温度下功率密度为118 mW/mm^(2),且在15 Hz的工作频率下有全调制深度。这些结果表明,这种红外光源在红外气体传感器中的应用具有巨大潜力。

Currently,there is a growing demand for gas monitoring in industrial field.Among various gas sensors,infrared sensors have gained widespread development and application due to their advantages of high precision and selectivity.Infrared emitter is the key component in infrared gas sensors,and its emissivity determines the performance of the sensor.Traditional methods to improve the emissivity include the production of surface microstructures and the addition of high-absorption nanomaterials.However,these methods can lead to increased costs and manufacturing complexity.A novel MEMS infrared emitter is proposed,which utilizes textured dielectric films to enhance infrared absorption and reduce thermal conduction to increase emissivity.The textured dielectric films are fabricated by a simple hard-molding process,which is low cost and compatible with conventional infrared emitter fabrication.The fabricated infrared emitters can achieve more than 99%emissivity in 2-20μm.The radiation area of the infrared emitter is 1.4 mm×1.5 mm,it can achieve a working temperature of 425°C with a power density of 118 mW/mm^(2) and has full modulation depth at the working frequency of 15 Hz.These results exhibit that this infrared emitter has great potential for application in infrared gas sensors.