Wide-band gap semiconductors for noncontact thermometry

The advantages achieved in two-color optical pyrometry using wide-band gap semiconductors (e.g., silicon carbide, gallium arsenide) and silicon-based photosensors for short- and long-wavelength light detection, respectively, are demonstrated here. Spectral responsivities of Si-, SIC-, and GaN-based photodiodes are used to evaluate the performances of a simple ratio pyromet er. Compared to conventional near-infrared ratio pyrometers, it is shown th at high-energy photon detection is able to reduce temperature measurement e rrors-mainly induced by spectral variation of the target emissivity-by more than 1 order of magnitude and allows increased output dynamics of the pyro meter of up to 4 orders of magnitude. (C) 2001 American Vacuum Society.