Review of micromachined thermopiles for infrared detection

TLDR

Thermopiles have recently attracted growing commercial interest in infrared sensing. The paper provides an overview of micromachined thermopiles, explaining the motivation for miniaturized detectors and the underlying physical interrelations. The review discusses the Seebeck effect, key physical parameters, noise sources, figures of merit, and material systems, fabrication techniques, and micromachined structures relevant to thermopile design. The authors highlight various applications and assess their future potential.

Abstract

During the last few years, thermopiles have come increasingly under the spotlight of commercial infrared sensing. This growing interest has motivated us to write an overview of micromachined thermopiles. The first part deals with the Seebeck effect and discusses the most important physical parameters with their interactions. We also describe the main noise sources and give a derivation of the figures of merit and their relevance for thermopile detectors. In the second part, a number of material systems, techniques and micromachined structures are discussed on the basis of different examples. We explain the motivation behind miniaturized thermopile detectors and give a functional explanation of physical interrelations. Finally, different applications are presented and discussed in terms of their future potential.