Formation and new functions of three-dimensional Si structure in silicate glasses by local structural modification

提出了将金属Al混合到硅酸盐玻璃的起始材料中作为在玻璃中形成Si结构的手段。我们证实，硅纳米晶体的空间选择性沉积在硅酸盐玻璃通过铝热反应引发的飞秒激光脉冲。通过激光照射，小的Si颗粒被转化成较大的，但仍然是微米尺寸的Si颗粒。由于热处理促进了铝热反应，这些结构生长为微米尺寸的颗粒。我们讨论了聚焦激光脉冲的照射对激光照射区硅沉积过程的影响。局部高温高压和冲击波的产生似乎是非常重要的，在形成富硅结构，有助于硅颗粒的生长。通过产生冲击波和富Al结构的存在的钙离子的扩散对于形成富Si结构如Si簇是重要的，这是通过使用局部高温连续破坏Si-O键来实现的。这些发现为硅集成器件和硅光子学领域开辟了新的可能性。

Mixing metallic Al into the starting material for silicate glass is proposed as a means of forming Si structures in glass. We confirmed that Si nanocrystals are space-selectively deposited in silicate glass via a thermite reaction triggered by femtosecond laser pulses. Small Si particles were transformed into larger, but still micrometer sized, Si particles by laser irradiation. These structures grew to micro-size particles due to the thermite reaction promoted by heat treatment. We discuss what effect the irradiation of the focused laser pulse had on the Si deposition process in the laser-irradiated region. Localized high temperatures and pressures and generation of shock waves appear to be very important in forming Si-rich structures that contribute to the growth of Si particles. The diffusion of calcium ions by the generation of shock waves and the presence of Al-rich structures is important for forming Si-rich structures such as Si clusters, which is achieved by continuously breaking Si-O bonds using localized high temperatures. These findings have opened up new possibilities in the field of Si-integrated devices and Si photonics.