Review of micromachined thermopiles for infrared detection

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.