Scintillator, P-47, ETEC, each

YAP (Yttrium Aluminum Perovskite activated by Ce3+) shares the same advantages as YAG but is more efficient in terms of light output than YAG crystals. As well, the emission spectrum peaks at about 378nm, and this corresponds closely to the maximum sensitivity of the S11 photocathode which in general is used in most scanning electron microscopes. (There would be more improvement in signal by using a YAP crystal rather than YAG in these microscopes). The decay time of YAP (40ns) is faster than YAG (80ns) so its overall performance is superior to YAG. YAP crystals should be coated with 50nm of aluminum prior to use.