Ambient temperature or moderately cooled semiconductor hot electron bolometer for mm and sub-mm regions

Abstract

A model of semiconductor hot electron bolometer (SHEB), in which electromagnetic radiation heats only electrons in narrow-gap semiconductor without its lattice slow-response heating, is considered. Free carrier heating changes the generation-recombination processes that are the reason of semiconductor resistance rise. It is estimated, that Hg0.8Cd 0.2Te detector noise equivalent power (NEP) for mm and sub-mm radiation wavelength range can reach NEP 10-11 W at Δf = 1 Hz signal gain frequency bandwidth. Measurements performed at electromagnetic wave frequencies v = 36, 39, 55, 75 GHz, and at 0.89 and 1.58 THz too, with non-optimized Hg0.8Cd0.2Te antenna-coupled bolometer prototype confirmed the basic concept of SHEB. The experimental sensitivity Sv 2 V/W at T = 300 K and the calculated both Johnson-Nyquist and generation-recombination noise values gave estimation of SHEB NEP 3.5 × 10-10 W at the band-width Δf = 1 Hz and v = 36 GHz. © 2008 Association of Polish Electrical Engineers.