The application of non-equilibrium transport techniques to narrow-gap
semiconductor materials has produced practical, negative luminescent d
evices. These structures contravene Kirchhoff's law because they will
absorb infrared radiation in a limited band without emitting it. They
have many potentially important applications which include toxic gas s
ensing, cold shields for IR detectors, radiometric reference sources a
nd dynamic infrared scene projectors. (C) 1997 Published by Elsevier S
cience B.V.