Controlled Synthesis of Terbium-Doped Colloidal Gd<sub>2</sub>O<sub>2</sub>S Nanoplatelets Enables High-Performance X-ray Scintillators
Khursand E. Yorov, Saidkhodzha Nematulloev, Bedil M. Saidzhonov, Maxim S. Skorotetcky, Azimet A. Karluk, Bashir E. Hasanov, Wasim J. Mir, Tariq Sheikh, Luis Gutiérrez‐Arzaluz, Maximilian Emanuel Maria Phielepeit, Nawal Ashraf, Robert H. Blick, Omar F. Mohammed, Mehmet Bayındır, Osman M. Bakr
Abstract
Terbium-doped gadolinium oxysulfide (Gd 2 O 2 S:Tb 3+ ), commonly referred to as Gadox, is a widely used scintillator material due to its exceptional X-ray attenuation efficiency and high light yield. However, Gadox-based scintillators suffer from low X-ray spatial resolution due to their large particle size, which causes significant light scattering. To address this limitation, we report the synthesis of terbium-doped colloidal Gadox nanoplatelets (NPLs) with near-unity photoluminescence quantum yield (PLQY) and high radioluminescence light yield (LY). In particular, our investigation reveals a strong correlation between PLQY, LY, particle size, and Tb 3+ concentration. Our synthetic approach allows precise control over the lateral size and thickness of the Gadox NPLs, resulting in a LY of 50,000 photons/MeV. Flexible scintillating screens fabricated with the solution-processable Gadox NPLs exhibited a 20 lp/mm X-ray spatial resolution, surpassing commercial Gadox scintillators. These high-performance and flexible Gadox NPL-based scintillators enable enhanced X-ray imaging capabilities in medicine and security. Our work provides a framework for designing nanomaterial scintillators with superior spatial resolution and efficiency through precise control of dimensions and dopant concentration.