Lithium Tin Sulfide—a High‐Refractive‐Index 2D Material for Humidity‐Responsive Photonic Crystals
Lithium Tin Sulfide—a High‐Refractive‐Index 2D Material for Humidity‐Responsive Photonic Crystals
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DOI：
10.1002/adfm.201705740
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发表时间：
2018-04
影响因子：
19
通讯作者：
K. Szendrei‐Temesi;O. Sanchez-Sobrado;S. Betzler;Katharina M. Durner;Tanja Holzmann;B. Lotsch
中科院分区：
文献类型：
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作者：
K. Szendrei‐Temesi;O. Sanchez-Sobrado;S. Betzler;Katharina M. Durner;Tanja Holzmann;B. Lotsch
除了二氧化钛之外，扩大新型刺激响应、高折射率（RI）材料的组合是改善现有光子器件光学质量和传感性能的关键。本文介绍了硫化锡锂（LTS）纳米片作为一种新型的溶液可加工的超高RI材料（n = 2.50），它可以用湿化学沉积方法铸造成均匀的薄膜。由于其二维形态，LTS纳米片薄膜能够响应相对湿度的变化而膨胀。将LTS纳米片集成到基于TiO2， SiO2，纳米颗粒或H3Sb3P2O14纳米片的Bragg堆叠（BSs）中，可以在低于1 μ m的极低器件厚度下提供高光学质量的多层系统。由于LTS纳米片的超高RI和薄膜的高透明度，基于多孔二氧化钛作为低RI材料的BSs首次被实现，在光管理器件中显示出潜在的应用前景。此外，据报道，基于SiO2和LTS纳米片的BSs实现了最高的RI对比度。最后，基于LTS和H3Sb3P2O14纳米片的全纳米片BS具有优异的膨胀性能，这预示着新一代具有极高灵敏度的湿度传感器的出现。
Extending the portfolio of novel stimuli‐responsive, high‐refractive‐index (RI) materials besides titania is key to improve the optical quality and sensing performance of existing photonic devices. Herein, lithium tin sulfide (LTS) nanosheets are introduced as a novel solution processable ultrahigh RI material (n = 2.50), which can be casted into homogeneous thin films using wet‐chemical deposition methods. Owing to its 2D morphology, thin films of LTS nanosheets are able to swell in response to changes of relative humidity. Integration of LTS nanosheets into Bragg stacks (BSs) based on TiO2, SiO2, nanoparticles or H3Sb3P2O14 nanosheets affords multilayer systems with high optical quality at an extremely low device thickness of below 1 µm. Owing to the ultrahigh RI of LTS nanosheets and the high transparency of the thin films, BSs based on porous titania as the low‐RI material are realized for the first time, showing potential application in light‐managing devices. Moreover, the highest RI contrast ever realized in BSs based on SiO2 and LTS nanosheets is reported. Finally, exceptional swelling capability of an all‐nanosheet BS based on LTS and H3Sb3P2O14 nanosheets is demonstrated, which bodes well for a new generation of humidity sensors with extremely high sensitivity.