Diode and phosphor soft x-ray detectors: Studies of surface recombination, damage, and intensity effects in conversion efficiencies

Miscellaneous · Wed Jan 01 00:00:00 EST 1992

OSTI ID:7014777

Husk, D E

The author has measured the linearity of ZnS:Ag and Y[sub 2]O[sub 2]S:Eu over some 9 orders of magnitude of intensity. The photons-out per photon-in, [open quote]absolute quantum efficiency[close quote], of Y[sub 2]O[sub 2]S:Eu was found to be linear over this range while the expected nonlinearity of ZnS:Ag was measured in terms of absolute flux. The absolute quantum efficiency of 4 photodiodes was measured in the soft x-ray regime. The structure in the efficiency vs energy curves for the diodes was explained through the use of a model that involves carrier diffusion length, thickness of the surface layer, bulk gain of the diode, reflection coefficient and surface recombination velocity. The stability of the diodes of soft x-ray flux was also measured. Further he has measured the quantum efficiency of sodium salicylate from 70 to 280 eV. He has been able to fit a model to this efficiency using carrier diffusion length, bulk gain of the diode, the reflection coefficient and surface recombination velocity. By extending this model to low energies the author has explained the different shapes of the efficiency curves reported in the literature as being due to different surface recombination velocities. He has also explained the low energy [open quote]damage[close quote] reported in the literature as being due to changing surface recombination velocity. In addition, he has measured a change in the bulk quantum efficiency that involves second-order kinetics of the incident flux. Finally the author also measured the absolute quantum efficiency of 16 phosphors over the range from [approximately]20 to 500 eV. The stability as a function of intensity over various ranges has also been measured.

• Research Organization: Virginia Univ., Charlottesville, VA (United States)
• OSTI ID: 7014777
• Resource Relation: Other Information: Thesis (Ph.D.)
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
PHOSPHORS
QUANTUM EFFICIENCY
RECOMBINATION
PHOTODIODES
SOFT X RADIATION
X-RAY DETECTION
EUROPIUM
SALICYLIC ACID
SILVER
YTTRIUM OXIDES
YTTRIUM SULFIDES
ZINC SULFIDES
CARBOXYLIC ACIDS
CHALCOGENIDES
DETECTION
EFFICIENCY
ELECTROMAGNETIC RADIATION
ELEMENTS
HYDROXY ACIDS
INORGANIC PHOSPHORS
IONIZING RADIATIONS
METALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
RADIATION DETECTION
RADIATIONS
RARE EARTHS
SEMICONDUCTOR DEVICES
SEMICONDUCTOR DIODES
SULFIDES
SULFUR COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
X RADIATION
YTTRIUM COMPOUNDS
ZINC COMPOUNDS
664200* - Spectra of Atoms & Molecules & their Interactions with Photons- (1992-)
665000 - Physics of Condensed Matter- (1992-)