The THz Catastrophe. Part 1: Discrepancy Between Planck’s Law and Experiments on Silicon Wafers

Abstract

The thermal energy radiated by silicon wafers is characterized experimentally in the mm and sub-mm wave ranges. The samples are heated and the energy they radiate thermally is captured by horn antennas and then detected. The energy radiated is in the tens and hundreds of pico-Joule per second ranges. The Zero Bias Schottky Detectors adopted are characterized by Noise Equivalent Powers in the few pico-watts, rendering the measurements possible. For moderate conductivities the measurements show a descending pattern as a function of the frequency which is not in line with expectations from Planck's law. Should these experiments have been available 120 years ago, the community of the time would probably have been concerned about avoiding the THz catastrophe, rather than the Ultraviolet catastrophe! A companion paper provides a possible theoretical classical explanation of the results [1].