Use of a ZnS : Er , Cu Cathodoluminescent Phosphor with Spectral Filtering for Contrast Enhancement

Abstract

It is shown that the contrast of a narrow‐line emitting cathodoluminescent normalZnS:normalEr,normalCu phosphor may be considerably improved through the use of a spectral filter whose bandpass is coincident with the phosphor emission spectrum. Such enhancement is due to the selective exclusion of ambient light not in the spectral region of the phosphor emission. The erbium‐activated zinc sulfide phosphor reported here has a primary emission from the 2H11/2→4I15/2 transition. The contrast enhancement of the rare earth phosphor achieved through the utilization of this method is reported. It is compared with the contrast enhancement of P‐2, a broadband emitting phosphor. It is shown that the efficiency requirement for the rare earth phosphor is considerably less than that of the broadband emitting phosphor, for the same degree of viewability.

Photo‐ and Cathodoluminescent Properties of Erbium‐Doped Thiogallates

“…Evidence for a bound exciton around a transition metal ion was given by the work of Kawai and Hoshina (5): they found exciton lines in excitation spectra of ZnS:Mr~2+. The origin of carrier-trapping potential can be attributed to a difference between the ionization potentials of the impurity atoms and host atoms (2)(3)(4)(5).…”

“…Owing to the size and mass of sulfur atoms, sulfides can also satisfy the two above requirements. Under cathode-ray excitation, ZnS, for example, coactivated with Cu + and Er 3+ does show the 4S3/2, 2Hll/2 -> 4115/2 lines in addition to the usual ZnS:Cu band (5). Sulfides are generally efficient cathode-ray phosphors (6,7); it is therefore attractive to investigate the luminescent properties of Er 3 + in sulfide lattices.…”

CURIOSITAS AND PSYCHE'S GROWTH IN APULEIUS' METAMORPHOSES

“…Her curiositas here is considered by some scholars as 'immature and trivial' 72 or a 'religious violation' similar to the first incidence when she sees her husband's real form. 73 However, she opens the box of beauty lotion in the hope of pleasing her divinely beautiful lover. Her goal behind curiositas this time is the same as that of her earlier commitment to masculus animus (6.5), to win Cupid back.…”