Zhang Zhaojun, Suchan Klara, Li Jun, Hetherington Crispin, Kiligaridis Alexander, Unger Eva, Scheblykin Ivan G, Wallentin Jesper
Synchrotron Radiation Research and NanoLund, Department of Physics, Lund University, Box 124, Lund 22100, Sweden.
Chemical Physics and NanoLund, Department of Chemistry, Lund University, Box 124, Lund 22100, Sweden.
J Phys Chem C Nanomater Interfaces. 2021 Mar 4;125(8):4860-4868. doi: 10.1021/acs.jpcc.0c11217. Epub 2021 Feb 11.
Metal halide perovskites show great promise for a wide range of optoelectronic applications but are plagued by instability when exposed to air and light. This work presents low-temperature solution growth of vertically aligned CsPbBr nanowire arrays in AAO (anodized aluminum oxide) templates with excellent stability, with samples exposed to air for 4 months still exhibiting comparable photoluminescence and UV stability to fresh samples. The single-crystal nanowire length is adjusted from ∼100 nm to 5 μm by adjusting the precursor solution amount and concentration, and we observe length-to-diameter ratios as high as 100. Structural characterization results indicate that large-diameter CsPbBr nanowires have an orthorhombic structure, while the 10 nm- and 20 nm-diameter nanowires adopt a cubic structure. Photoluminescence shows a gradual blue-shift in emission with decreasing nanowire diameter and marginal changes under varying illumination power intensity. The CsPbBr-nanowires/AAO composite exhibits excellent resistance to X-ray radiation and long-term air storage, which makes it promising for future optoelectronic applications such as X-ray scintillators. These results show how physical confinement in AAO can be used to realize CsPbBr nanowire arrays and control their morphology and crystal structure.
金属卤化物钙钛矿在广泛的光电子应用中显示出巨大的潜力，但在暴露于空气和光时会受到不稳定性的困扰。这项工作展示了在具有优异稳定性的阳极氧化铝（AAO）模板中低温溶液生长垂直排列的CsPbBr纳米线阵列，样品在空气中暴露4个月后仍表现出与新鲜样品相当的光致发光和紫外线稳定性。通过调节前驱体溶液的量和浓度，将单晶纳米线的长度从约100nm调整到5μm，并且我们观察到长径比高达100。结构表征结果表明，大直径的CsPbBr纳米线具有正交结构，而直径为10nm和20nm的纳米线采用立方结构。光致发光显示随着纳米线直径减小发射逐渐蓝移，并且在不同光照功率强度下变化很小。CsPbBr纳米线/AAO复合材料对X射线辐射和长期空气储存表现出优异的抗性，这使其在诸如X射线闪烁体等未来光电子应用中具有前景。这些结果表明了如何利用AAO中的物理限制来实现CsPbBr纳米线阵列并控制其形态和晶体结构。
