Nakakura Shuhei, Arif Aditya Farhan, Machida Keisuke, Adachi Kenji, Ogi Takashi
Department of Chemical Engineering , Hiroshima University , 1-4-1 Kagamiyama , Higashihiroshima , Hiroshima 739-8527 , Japan.
Ichikawa Research Center , Sumitomo Metal Mining Co., Ltd , 3-18-5 Nakakokubun , Ichikawa , Chiba 272-8588 , Japan.
Inorg Chem. 2019 Jul 15;58(14):9101-9107. doi: 10.1021/acs.inorgchem.9b00642. Epub 2019 Jun 27.
Cesium tungsten bronzes (CsWO) have attracted much attention as a near-infrared absorbing material. We report the successful synthesis of highly crystalline and high purity CsWO nanoparticles through a spray pyrolysis route. Careful analyses disclosed the presence of cationic defects, that is, a tungsten deficiency and insufficient Cs doping in the CsWO nanoparticles. These cationic defects can be controlled by facile heat treatment in a mildly reducing atmosphere. In particular, we clarify that the tungsten deficiency is a key factor among the cationic defects to obtain high near-infrared absorption properties. Furthermore, this study clearly demonstrates the precise tunability of the optical properties by means of the lattice constants of the CsWO crystal. The realized range of lattice constants is significantly wider than those previously reported. These findings should contribute to the engineering of CsWO structure and properties.
铯钨青铜（CsWO）作为一种近红外吸收材料备受关注。我们报告了通过喷雾热解路线成功合成出高结晶度和高纯度的CsWO纳米颗粒。仔细分析发现CsWO纳米颗粒中存在阳离子缺陷，即钨缺陷和铯掺杂不足。这些阳离子缺陷可通过在温和还原气氛中进行简便的热处理来控制。特别是，我们阐明了钨缺陷是获得高近红外吸收性能的阳离子缺陷中的关键因素。此外，本研究清楚地证明了通过CsWO晶体的晶格常数可精确调节光学性质。实现的晶格常数范围比先前报道的要宽得多。这些发现应有助于CsWO结构和性能的工程设计。
