Development of solid state infrared emitters for gas detection applications

The gas industry needs low-cost portable instruments to measure the concentration of gases in air in order to monitor combustion efficiency, detect leaks, and prevent hazardous conditions. Detection of methane has already been demonstrated using infrared emitting diodes (IREDs) as the radiation source; current research extends this technique to the detection of carbon monoxide and carbon dioxide. Researchers have successfully grown a ternary indium-arsenic-antimony semiconductor by a steady-state liquid-phase epitaxial method to be used as a radiation source. Layer compositions measured with the electron microprobe agree well with predictions based on the calculated phase diagram. Photoluminescence measurements at -320/sup 0/F (77 K) show a shift in emission wavelength that at 80/sup 0/F (300 K) will correspond to the 4.2-micrometer absorption maximum of carbon dioxide.