Project funded by the National Science Centre (NCN) under the OPUS 24 competition
Project number: 2022/47/B/ST5/01966
Project value: 1,520,820.00 PLN
Funding amount: 1,520,820.00 PLN
Project duration: 02/10/2023 – 01/10/2026
Project manager: Muhammad Danang Birowosuto, PhD
Scintillation materials are sensitive to ionizing radiation and are widely used in various detection systems, including medical imaging, homeland security, high-energy physics (HEP) calorimetry, energy applications, industrial control, oil-well logging, and quantum sensors.
Some scintillators exhibit properties enabling applications beyond static radiation imaging — such as time-of-flight (TOF) measurement, spectroscopy, and ultrafast multi-frame radiation imaging. Two key properties determine their performance: light yield (the number of visible photons produced per unit of deposited radiation energy) and decay time (the speed at which photons are emitted after excitation).
Both parameters influence coincidence time resolution (CTR) in positron emission tomography (PET) and output count rate (OCR) in photon-counting computed tomography (PCCT) and fast spectral X-ray imaging. CTR values below 30 ps significantly enhance TOF-PET image quality by improving the signal-to-noise ratio, while OCR > 20 Mcps/pixel in PCCT would surpass the performance of current CdTe/CZT semiconductor technologies.
The best commercial PET scintillator, Lu₂SiO₅:Ce (LSO:Ce), achieves a CTR of 60 ps, but its cost (~426 EUR for a 20×20×20 mm³ crystal) makes complete TOF-PET systems extremely expensive. Furthermore, progress in PCCT using existing semiconductor technologies is limited due to the need for more stable and reliable detectors.
Project concept
Inspired by advances in photovoltaics, this project proposes solution-processable perovskite scintillators as a cost-effective alternative to LSO:Ce — potentially reducing costs by a factor of up to 50. Two promising candidates are:
2D hybrid organic–inorganic perovskite crystals (2D HOIP)
Lead-free all-inorganic perovskite crystals (AIP)
Current 2D HOIP scintillators exhibit a light yield >20 photons/keV and decay times <5 ns, resulting in a CTR of about 80 ps — slightly inferior to LSO:Ce but with an absorption length only four times greater. Lead-free AIP crystals, with an absorption length comparable to LSO:Ce, achieve up to 100 photons/keV, yet their decay times (~50 ns) yield CTR values exceeding 150 ps.
To achieve the target 30 ps CTR, the light yield of 2D HOIP and AIP scintillators must be enhanced three- to fivefold. For PCCT, current 2D HOIP crystals already reach 10 Mcps/pixel, only two times lower than state-of-the-art semiconductor technology.
Project objective
The Fapurite project aims to overcome these limitations by employing nanophotonics, specifically resonant nanostructures, to enhance light emission through the Purcell effect. This approach will simultaneously improve light yield and decay time, enabling a reduction in CTR and an increase in OCR, paving the way for faster and more efficient perovskite-based scintillators for advanced imaging technologies.
