Abstract
Infrared (IR) detectors for the long-wave infrared range (LWIR) based on nanostructured thermocouples exhibit response times in the order of picoseconds and will open new areas of applications in THz broadband communication systems. We show experimental evidence for a nonzero relative Seebeck coefficient between the narrow and the wide wire segments of single-material thermocouples, and we investigate the thermal dynamics of nano-thermocouples for a substrate heated by a nanostructured thermocouple patch. Due to its low thermal capacity a mesoscopic thermocouple is an extremely fast square-law detector with cutoff frequencies up to several hundred GHz.