Dangling-bond-free, chemically anisotropic semiconductors for ultrahigh-resolution X-ray imaging

Interfacial defects, particularly those of intergranular origin, are a persistent challenge limiting the performance of modern optoelectronic devices. Conventional three-dimensional and low-dimensional (two- or one-dimensional) semiconductors all suffer from surface or edge-related bonding discontinuities that degrade the carrier dynamics and optical efficiency. Here we report on a new semiconductor design strategy based on zero-dimensional structured materials, which inherently lack dangling bonds along all crystallographic directions. By introducing anisotropic chemical bonding within the zero-dimensional framework, we can achieve customizable morphologies—such as rods—without compromising the isotropic and defect-free electronic properties. Using the uranyl-based halide Cs 2 UO 2 Cl 4 as a model, we exploit the bonding disparity between U=O and U–Cl to drive anisotropic crystal growth. When applied to X-ray scintillation imaging, columnar structured Cs 2 UO 2 Cl 4 achieved a high spatial resolution (34 lp mm −1 ). This work introduces a generalizable approach for decoupling material geometry and electronic dimensionality, offering a new platform for high-performance, defect-tolerant semiconductors.