Flexible and transparent silicon nanoparticle/polymer composites with stable luminescence.
Flexible and transparent silicon nanoparticle/polymer composites with stable luminescence.
复制标题
DOI：
10.1002/asia.200900403
复制
发表时间：
2010-01
期刊：
影响因子：
--
通讯作者：
Keisuke Sato;N. Fukata;K. Hirakuri;M. Murakami;T. Shimizu;Y. Yamauchi
中科院分区：
文献类型：
--
作者：
Keisuke Sato;N. Fukata;K. Hirakuri;M. Murakami;T. Shimizu;Y. Yamauchi
目前，半导体纳米颗粒（NPs）由于其尺寸依赖的光学和电子特性，作为下一代荧光材料吸引了极大的兴趣。[1]具有半导体NP的柔性和透明发光体在未来的创新应用中需求量很大，包括电致发光显示器，[2]诊断成像系统，[3]愈合设备，[4]以及导管和隐形眼镜形式的各种器官（即动脉，血管，眼睛，心脏和肺）中的手术旁路。[5]特别是，由柔性和透明发光体组成的聚合物基复合材料应该非常适用于柔性显示模块，[6]用于导管和隐形眼镜的生物医学材料，[7]以及保护材料免受环境污染物的影响，[8]因为聚合物基质具有许多优点，例如生物相容性，耐化学性，重量轻，硬度低。[9]在这种情况下，嵌在聚合物基质中的半导体纳米粒子的光学和毒理学性质是绝对关键的。众所周知，半导体纳米粒子，包括CdS，[10] CdSe，[11]和CdTe，[12]具有独特的特征，即宽光激发，尺寸可调发光和高量子产率。[13]然而，基于Cd的NPs仅在有限数量的领域中使用，因为重金属离子（Cd离子）对生理和人类生态环境具有高度毒性。[14]这种严重的问题已经引发了持续和迫切的发展，纳米粒子组成的无毒和安全的材料替代镉。Si-NP显示出非细胞毒性特性[15]以及通过在室温下将平均直径从3.0 nm减小到1.9 nm而从红光到蓝光的连续发光。[16]然而，遇到了实际问题，例如，在大气和/或溶剂中储存时量子产率的降低和/或发光颜色的变色仍然没有解决，这降低了Si-NP的上级优点。[17]这些现象主要是由与界面缺陷对应的非辐射复合位点的产生引起的，这些界面缺陷是所谓的Pb中心，[18]由于氧化反应，在Si-NP的结晶Si核心和表面氧化物层之间。[19个]
Currently, semiconductor nanoparticles (NPs) are attracting great interest as next-generation fluorescent materials owing to their size-dependent optical and electronic properties.[1] Flexible and transparent luminants with semiconductor NPs are much in demand toward future innovative applications, including electroluminescent displays,[2] diagnostic imaging systems,[3] healing devices,[4] and a surgical bypass in a variety of organs (ie, arteries, blood vessels, eyes, heart, and lungs) in the form of catheters and contact lenses.[5] In particular, polymer-based composites consisting of flexible and transparent luminants should be extremely useful for flexible display modules,[6] biomedical materials used for catheters and contact lenses,[7] and protecting materials from environmental pollutants,[8] because the polymer matrix has many advantages, such as biocompatibility, chemical resistance, light weight, and low hardness.[9] In such cases, the optical and toxicological properties of the semiconductor NPs embedded in the polymer matrix are absolutely critical.It is generally known that semiconductor NPs, including CdS,[10] CdSe,[11] and CdTe,[12] possess unique features, namely, broad photoexcitation, size-tunable luminescence, and high quantum yield.[13] However, Cd-based NPs are utilized in only a limited number of fields, because heavymetal ions (Cd ions) are highly toxic to physiological and human ecological environments.[14] Such a serious problem has triggered the continual and urgent development of NPs consisting of nontoxic and safe materials alternative to Cd. Si-NPs show non-cytotoxic properties [15] as well as continuous multicolor luminescence from red to blue light by the reduction of the mean diameter from 3.0 to 1.9 nm at room temperature.[16] However, practical issues have been encountered, for example, the degradation of quantum yield and/or discoloration of luminescence color under storage in an atmosphere and/or a solvent remain unsolved, which devalues the superior advantages of the Si-NPs.[17] These phenomena are mainly caused by the generation of nonradiative recombination sites corresponding to the interfacial defects, which are so-called Pb centers,[18] between the crystalline Si core of the Si-NPs and surface oxide layer due to the oxidation reaction.[19]