Reportedly, zinc sufide (ZnS) doped with Ag or Al or Cu is the most energy-efficient scintillator: one estimate says it's 30 %, that is, for an optimized composition (doping, crystal size, etc.) a single 10 keV electron fully stopped in a thin layer of this material results in the emission of ~ 1500 photons of nominal ~ 2 eV, a total of 3 keV in photon energy, over 4 pi. I have found numerous references with data, for all kinds of scintillators (for short-emission time materials at e.g., scintillator.lbl.gov, which does not include ZnS because its long emission time excludes it from this list), but very few (and old) references to a theory (e.g., Klasen, 1947).
What is the best place to find such a theory, preferably starting with something primitive that a non-solid-state physicist can follow?
Dear Nino
You should separate the quantum yield of luminescence and yield of energy. Yield of energy may be close, but not to exceed 100%.
Best regards from Siberia.
V. Mironov
Dear Vasily,
thank you for the reaction, although it isn't an answer that I can interpret. I assume that the the quantum yield of luminescence is the number of photons emitted by the recombination of an electron caught in a trap, and a hole. Hence, it is unity if de-excitation can only occur through an electromagnetic transition, not an Auger process or something else. The energy yield, the energy in all the photons emitted as a result of a single electron that dumps its energy in the crystal, is of course less than unity, but it can be equal to unity only without losses. But, losses are always there. Some electrons may excite Zn's M-shell, or the L-shell electrons, and (if higher than about 9.659 keV, the K-shell; same with S. Then, there's electrical resistance (and eventually phonons), and the energy lost to whatever as the electron is caught. So, some energy must be lost. Where is all this nicely explained?
Dear Nino,
You yourself are all well explained. There simply must be (according to experimental conditions) are properly taken into account the contribution of each process.
Vasily
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