Improved Scintillation Detector Performance via a Method of Enhanced Layered Coatings

Increasing demand for better detection performance with a simultaneous reduction in size, weight and power consumption has motivated the use of compact semiconductors as photo-converters for many gamma-ray and neutron scintillators. The spectral response of devices such as silicon avalanche photodiodes (APDs) is poorly matched to many common high-performance scintillators. We have developed a generalized analytical method that utilizes an optical reference database to match scintillator luminescence to the excitation spectrum of high quantum efficiency semiconductor detectors. This is accomplished by the fabrication and application of a series of high quantum yield, short fluorescence lifetime, wavelength-shifting coatings. We show here a 22% increase in photoelectron collection and a 10% improvement in energy resolution when applying a layered coating to an APD-coupled, cerium-doped, yttrium oxyorthosilicate (YSO:Ce) scintillator. Wavelength-shifted radio-luminescence emission and rise time analysis are also discussed.