We report on recent developments of Nanostructured Organosilicon Luminophores (NOLs) and their application as highly efficient and fast wavelength shifters (WLS) in various types of elementary particles photodetectors. NOL consists of two types of covalently bonded via Si atoms organic luminophores with efficient Förster resonance energy transfer between them. NOLs combine the best properties of organic luminophores and inorganic quantum dots: high absorption cross-section and photoluminescence quantum yield (PLQY), low self-absorption, fast luminescence decay time, good solubility and processability, as well as low toxicity. A variety of organic luminophores allowed us to design and synthesize a library of NOLs, absorbing from 150 to 550 nm and emitting at the desired wavelengths from 390 to 650 nm. The luminescence decay time of NOLs can be as short as 0.8 ns at 90% PLQY.
NOLs were applied as highly efficient vacuum UV WLS for PMT and SiPM used in liquid argon detectors. WLS based on NOL covered on PMT allowed to increase the efficiency of Cherenkov light detection on 15%. Plastic scintillators containing NOLs were 50% more efficient and 40% faster as the standard ones. Fast and efficient NOL-based scintillating fibers (SciFi) emitting in blue and green regions with the decay time of 1.18 – 1.34 ns that is 2-5 times faster than the standard Kuraray SciFi were developed. NOL-containing WLS plates were used for efficient conversion of UV photons into visible light in fast pure CsI scintillators coupled with avalanche photodiodes. That allowed to rise 2-3 times the scintillation light output for upgrade of the end cap electromagnetic calorimeter of Belle II detector.
This work was supported by Federal Agency of Scientific Organizations and made in the framework of leading science school NSh-5698.2018.3.