Efficient Infrared-Thermal-Electric Conversion with Textured Dielectric Film

Converting more infrared energy into heat while reducing heat loss from dielectric film to silicon substrate is very attractive for infrared-thermal-electric sensors. Thin FLat Dielectric (FLDI) film is known to possess low thermal conductivity, which is a conventional candidate for controlling heat loss. Meanwhile, high infrared absorption nanomaterials are adopted to compensate for the relatively low absorptivity of the FLDI film. However, this combination method may cause large weight stress, fabrication incompatibility, and high cost. In this paper, a new TExtured DIelectric (TEDI) film is proposed to simultaneously improve the heat conduction and infrared absorption properties in a simple, effective, and CMOS-compatible way. The fabricated thermopile platform with TEDI film can achieve about 55% enhancement in output voltage response and responsivity as well as about 47% in detectivity compared to the controlled thermopile with FLDI film. By this thermopile platform, the demonstrated heat conduction of the TEDI film can be reduced by about 28% while the tested infrared absorption can be increased by about 12%. This work may provide a simple and effective method toward engineering light-weight and thermally insulating FLDI films into efficient infrared-thermal-electric materials for achieving high-performance infrared or thermal sensors.