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arXiv · 2302.05130

Nanocrystalline CaWO$_4$ and ZnWO$_4$ Tungstates for Hybrid Organic-Inorganic X-ray Detectors

Inga Pudza·Kaspars Pudzs·Andrejs Tokmakovs·Normunds Ralfs Strautnieks·Aleksandr Kalinko·Alexei Kuzmin
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Abstract

Hybrid materials combining an organic matrix and high-Z nanomaterials show potential for applications in radiation detection, allowing unprecedented device architectures and functionality. Herein, novel hybrid organic-inorganic systems were produced using a mixture of tungstate (CaWO$_4$ or ZnWO$_4$) nanoparticles with a P3HT:PCBM blend. The nano-tungstates with a crystallite size of 43 nm for CaWO$_4$ and 30 nm for ZnWO$_4$ were synthesized by the hydrothermal method. Their structure and morphology were characterized by X-ray diffraction and scanning electron microscopy. The hybrid systems were used to fabricate direct conversion X-ray detectors able to operate with zero bias voltage. The detector performance was tested in a wide energy range using monochromatic synchrotron radiation. The addition of nanoparticles with high-Z elements improved the detector response to X-ray radiation compared with that of a pure organic P3HT:PCBM bulk heterojunction cell. The high dynamic range of our detector allows for recording X-ray absorption spectra, including the fine X-ray absorption structure located beyond the absorption edge. The obtained results suggest that nanocrystalline tungstates are promising candidates for application in direct organic-inorganic X-ray detectors.

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Inga Pudza, Kaspars Pudzs, Andrejs Tokmakovs, Normunds Ralfs Strautnieks, Aleksandr Kalinko, Alexei Kuzmin. 2023-02-10. Nanocrystalline CaWO$_4$ and ZnWO$_4$ Tungstates for Hybrid Organic-Inorganic X-ray Detectors. https://doi.org/10.3390/ma16020667

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