Institute of Fluid Science, Tohoku University, Sendai, Miyagi, Japan.
Nanotechnology. 2012 Feb 17;23(6):065302. doi: 10.1088/0957-4484/23/6/065302. Epub 2012 Jan 17.
A sub-10 nm, high-density, periodic silicon-nanodisc (Si-ND) array has been fabricated using a new top-down process, which involves a 2D array bio-template etching mask made of Listeria-Dps with a 4.5 nm diameter iron oxide core and damage-free neutral-beam etching (Si-ND diameter: 6.4 nm). An Si-ND array with an SiO(2) matrix demonstrated more controllable optical bandgap energy due to the fine tunability of the Si-ND thickness and diameter. Unlike the case of shrinking Si-ND thickness, the case of shrinking Si-ND diameter simultaneously increased the optical absorption coefficient and the optical bandgap energy. The optical absorption coefficient became higher due to the decrease in the center-to-center distance of NDs to enhance wavefunction coupling. This means that our 6 nm diameter Si-ND structure can satisfy the strict requirements of optical bandgap energy control and high absorption coefficient for achieving realistic Si quantum dot solar cells.
采用一种新的自上而下工艺制备了亚 10nm、高密度、周期性硅纳米盘（Si-ND）阵列，该工艺涉及由李斯特菌-Dps 制成的二维阵列生物模板刻蚀掩模，其直径为 4.5nm，核心为氧化铁，且无损伤中性束刻蚀（Si-ND 直径：6.4nm）。具有 SiO(2)基质的 Si-ND 阵列由于 Si-ND 厚度和直径的精细可调性，表现出更可控的光学带隙能量。与缩小 Si-ND 厚度的情况不同，缩小 Si-ND 直径同时增加了光吸收系数和光学带隙能量。由于减小了纳米盘的中心到中心距离，增强了波函数耦合，因此光吸收系数变得更高。这意味着我们的 6nm 直径 Si-ND 结构可以满足实现实际硅量子点太阳能电池的光学带隙能量控制和高吸收系数的严格要求。
