On another front, there are some significant developments in phosphors
that are stimulated by the uv bands available from pure xenon. I'm
curious if anyone in this newsgroup is involved with this research and
if there are links they might provide to come up to speed with this
interesting area.
There has been and continues to be work in this area but I don't know
of any significant developments. The resonance line of Xenon has a
wavelength of 172 nm which translates to an energy of 7.214 eV per
photon. If you had a phosphor with a quantum efficiency of 1.0, you
would lose 66% of the photon energy when converting it to visible
light. We have to solve two key problems before we can have an
efficient Xe-based fluorescent lamp: First, we need a phosphor that
has good color rendition and a high quantum efficiency when excited by
172 nm photons, and this quantum efficiency must be significantly
greater than 1.0. Second, we need some sort of Xenon reservoir that
will serve the function now served by the excess liquid mercury we put
in all fluorescent lamps. (The active gas, be it Hg or Xe, will be
"consumed" through physical and chemical attachment and therefore must
be replaced to have long lamp life.)
Developments in quantum splitting phosphors suitable for use in
fluorescent lamps were discussed in the summer of 2001 at LS:9, The
9th International Symposium on the Science and Technology of Light
Sources, held at Cornell University. At that time, there were no
phosphors suitable for use in Xe-based fluorescent lamps. LS:10 is
scheduled for summer of 2004 at the University of Toulouse. (See:
http://www.ls-symposium.org/.) Hopefully more progress will be
reported at that time.