Nakamura Toshihiro, Yuan Ze, Adachi Sadao
Division of Electronics and Informatics, Faculty of Science and Technology, Gunma University, Kiryu, Gunma 376-8515, Japan.
Nanotechnology. 2014 Jul 11;25(27):275602. doi: 10.1088/0957-4484/25/27/275602. Epub 2014 Jun 24.
We demonstrate the higher-yield (one order of magnitude) preparation of blue-emitting colloidal Si nanocrystals with a diameter range of 1-3 nm by selective laser ablation of porous Si powder in an organic solution, compared with the ablation of bulk Si powder. This increase in yield is the result of the lower thermal conductivity and the larger surface area of porous Si. The prepared colloidal Si nanocrystal exhibits size-dependent, higher-lying bandgap energies and large radiative decay rates as a result of the quantum confinement effect. Reversible luminescence color change from blue to yellow and vice versa in the colloidal Si nanocrystal film is also observed, and this is attributed to the non-radiative inter-crystal energy transfer.
我们证明，与块状硅粉的烧蚀相比，通过在有机溶液中对多孔硅粉进行选择性激光烧蚀，可以制备出直径范围为1-3纳米的蓝光发射胶体硅纳米晶体，其产率更高（一个数量级）。产率的提高是由于多孔硅的热导率较低和表面积较大。由于量子限制效应，所制备的胶体硅纳米晶体表现出尺寸依赖性、更高的带隙能量和较大的辐射衰减率。在胶体硅纳米晶体薄膜中还观察到从蓝色到黄色以及反之亦然的可逆发光颜色变化，这归因于非辐射的晶间能量转移。
