| Jan 21, 2022 |
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(Nanowerk News) Organohalides are widely adopted to serve as halide source in traditional three-precursors route to obtain metal halide perovskite nanocrystals (PNCs).
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However, these organohalides are usually highly toxic, which is unfavorable for large-scale and sustainable use. Moreover, their efficacy in producing high-quality Pb-free PNCs is questionable.
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Recently, a research group led by Prof. HAN Keli from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) used all-inorganic nonhazardous GeX4 (X = Cl, Br, I) as ideal halide sources to synthesize both Pb-free and Pb-based PNCs with high optoelectronic quality.
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This study was published in Nano Letters (“Germanium Halides Serving as Ideal Precursors: Designing a More Effective and Less Toxic Route to High-Optoelectronic-Quality Metal Halide Perovskite Nanocrystals”).
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They found that Ge element wasn’t present in the final compositions, whereas material properties of the resulting NCs were improved, such as stronger photoluminescence emission and enhanced phase stability.
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They attributed these improved properties to a better control over the release of halide ions in Ge halide-based route, which helped the PNCs to form a regular crystal surface with less point defects.
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Moreover, the advantage of the proposed GeX4 approach in making ideal PNCs lied in their unique dielectric environment and thermodynamics.
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“It is foreseen that the GeX4-based synthesis could provide a yet unexplored less toxic path to produce these fascinating nanomaterials and tailor their optical properties without alerting their intrinsic structure,” said Prof HAN.
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