全无机钙钛矿CsPbBr3微米棒偏振荧光特性的研究

Investigation on Polarization Fluorescence Properties of All-Inorganic Perovskite CsPbBr3 Microrods

摘要:

以溴化铅、溴化铯为原料,通过化学气相沉积法(CVD)在Si/SiO₂衬底上制备得到全无机钙钛矿CsPbBr₃微米棒。采用X射线衍射(XRD)、扫描电子显微镜(SEM)对CsPbBr₃微米棒的晶体结构、形貌和组分进行表征,并通过光致发光光谱(PL)对样品的荧光偏振特性进行了测试。测试分析表明,制备的CsPbBr₃微米棒具有三角形截面,长度为15~25μm可控,形貌规则,结晶质量高,沿[001]方向结晶生长,室温下为立方相晶体结构；微米棒样品展现出良好的偏振依赖荧光发射,PL光谱呈现出180°偏振周期性变化,发射荧光偏振度为0.30,光电场限域效应是产生偏振荧光的主要机制。

Abstract:

All-inorganic perovskite CsPbBr₃ microrods were prepared on the Si/SiO₂ substrate by chemical vapor deposition (CVD) using lead bromide and cesium bromide as raw materials. The morphology, composition and crystal structure of the microrods were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), the polarization fluorescence properties of the samples were tested by the photoluminescence (PL) spectrum. The results reveal that the prepared CsPbBr₃ microrods have regular morphology with triangular cross sections and controllable lengths of 15~25μm, growing along the [001] direction. High crystal quality and cubic phase crystal structure at room temperature of the sample are confirmed. The CsPbBr₃ microrods display a good polarization-dependent fluorescence emission with a 180° polarization periodic change, and the calculated emission fluorescence polarization degree is 0.30. The confinement of optical electric field due to the difference in the dielectric constants is the main mechanism responsible for the polarization anisotropy.