ABSTRACT

Here we present green synthesis of highly luminescent Si/SiO${}_2$ nanoparticles having an average size of $12.8\pm 0.2\mathrm{nm}$ by one step reduction of 3-aminopropyltriethoxysilane using Actinidia deliciosa as a green reducing agent in water. These water dispersible nanoparticles present an absorption edge at 3.34 eV. An uneven surface oxidation of these nanoparticles appears due to which variable defect sites and their corresponding energy levels are involved in the emission processes. This is why, an excitation dependent emission in these nanoparticles is observed where by decreasing the excitation energy, the emission peak redshifts. The maximum emission quantum yield in these nanoparticles is found to be 27% at 350 nm when the reaction mixture was kept for 5 days. The emission energy and the intensity are found to be dependent on the reaction time due to which their quantum efficiencies also vary.

摘要

在这里，我们介绍了高发光Si / SiO的绿色合成${}_{\mathrm{2个}}$ 平均尺寸为 $12.8\pm 0.2\mathrm{纳米}$通过使用美味猕猴桃作为水中的绿色还原剂一步还原3-氨基丙基三乙氧基硅烷。这些水分散性纳米颗粒在3.34eV处具有吸收边缘。由于在发射过程中涉及到可变的缺陷位点及其相应的能级，因此出现了这些纳米颗粒的不均匀的表面氧化。这就是为什么在这些纳米颗粒中观察到依赖于激发的发射的原因，其中通过降低激发能，发射峰发生红移。当将反应混合物保持5天时，发现这些纳米颗粒的最大发射量子产率在350nm为27％。发现发射能量和强度取决于反应时间，由于它们的量子效率也变化。