虽然“非晶到晶体”的相变过程已经被广泛研究，但迄今为止，对涉及纳米尺度上的微观机制仍不完全了解。
近日，中国科学院福建物质结构研究所王元生研究员、林航研究员和福州大学刘明教授等人在Science China Materials发表研究论文，在含Cs-Pb-Br组分的磷酸盐玻璃体系中发现了一种与常见的热处理玻璃诱导析晶过程不同的通过力诱导-湿度介导的特殊析晶机制。
本文要点
1) 剪切力作用下，玻璃网络被破坏，产生了高能位点，这些高能位点吸收来自环境湿气的H2O分子/团簇，随后玻璃组分的水化过程促进了CsPbBr3纳米晶的析出。2) 微观力学检测结合共聚焦激光扫描显微成像技术，揭示CsPbBr3纳米晶的分布几乎复现了局域应力场的分布，并清晰地反映了裂纹扩展的传播路径。3) 这一特殊的晶化机制，进一步验证了钙钛矿玻璃在力传感和湿度传感方面的潜在新应用。本工作为了解玻璃中晶体的形核/生长以及了解玻璃脆性断裂过程中裂纹的传播动力学提供了独特的视角。![]()
Figure 1. CsPbBr3 nanocrystallization on a glass surface. (a) Luminescent photographs (under 365 nm UV light excitation) of the pulverized glass powders and the fractured cross section of the bulk glass in air (top panels; RH: 40%; the green luminescence from CsPbBr3 is observable) and in a glove box (bottom panels; RH: <0.03%; the blue color hue originates from the UV light source rather than from photoluminescence). (b) XRD curves of the bulk glass and pulverized glass powders ground under ambient conditions. (c) TEM image revealing the distribution of CsPbBr3 NCs in the glass matrix upon grinding. (d) High-resolution TEM image of a single particle. (e) SEM image of the scratched groove. (f) EDS point analyses of the glass matrix (Spot I) and single particles (Spot II). The Pt signal originates from Pt sprayed on the specimen surface to enhance the conductivity for SEM characterization. Some weak signals from glass components are detected in Spot II since the NCs are too small so that the electron beam irradiates a part of the glass matrix.![]()
Figure 2. Humidity-dependent CsPbBr3 nanocrystallization. Photoluminescence spectra of the pulverized glass samples with various PbO contents (10–30 mol%) under (a) 20% RH, (b) 30% RH, (c) 40% RH, (d) 60% RH, (e) 80% RH, and (f) 98% RH; (g) the corresponding 3D contour plot with the data at the peak intensity. (h) Line plots showing the dependence of the peak wavelength on the PbO content and humidity.Figure 3. Glass crystallization mechanism. Schematic illustration of the force-driven moisture-mediated nanocrystallization process of CsPbBr3 on a glass surface.![]()
Figure 4. Application exploration. (a) CLSM images of the residual scratch groove upon the application of a constant normal force (100–800 mN). The corresponding luminescence distribution grayscale maps are also presented in the bottom panels. (b) The relationship between the vertical load and the integral intensity derived from grayscale mapping. (c) Illustration of handwriting authentication by using the developed perovskite glass as a “pen”. (d) Luminescent photos of the written English word “force” obtained by using a “glass pen” under different forces (λex = 365 nm). (e) Luminescent photos of the “rain drop” pattern fabricated from perovskite glass powders and PDMS under different ambient humidities (λex = 365 nm). (f) The corresponding luminescent spectra showing redshifts with increasing humidity. (g) Plot of the integral luminescent intensity versus humidity.Peng Gao, Hang Lin, Pengfei Wang, Ming Liu, Ju Xu, Yao Cheng, Yuansheng Wang. Force-driven moisture-mediated CsPbBr3 nanocrystallization from amorphous glass. Sci. China Mater. (2024).https://doi.org/10.1007/s40843-024-2954-0
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