矽塊材在室溫下為高熱導率材料，熱導率約為150 W/m-K，導致矽塊材ZT值只有0.01，為不良的熱電材料，降低矽的熱導率才能提升ZT值，因此，一維奈米結構成為熱門的研究。相較於塊材，一維矽奈米線結構表面容積比大，聲子傳遞受到侷限，導致聲子散射，有效降低熱導率。本研究使用低摻雜p-type及重摻雜n-type (100)矽晶片，以金屬輔助化學蝕刻法(Mental-assisted chemical etching)製成單晶粗糙的矽奈米線，直徑約為150-250nm，熱導率明顯下降，經氧電漿蝕刻，低摻雜奈米線電導率電導率會上升。 ;The thermal conductivity of bulk silicon is 150Wm-1K-1 at room temperature. It is considered as poor thermoelectric material. The ZT is just 0.01 due to its high thermal conductivity. Thus, one dimensional nanostructure has become a good study to solve this problem. Comparing with bulk, there have large surface to volume ratio of one dimension nanostructure. The thermal conductivity reduced by the phonon scattering in the boundary of nanowires. It is helpful to reduce the thermal conductivity. In our study, we use MACE method to fabricate single rough silicon nanowires from lightly doped p-type and heavily doped n-type (100) wafers. The diameter of silicon nanowires are about 150-250nm. The thermal conductivity was decreasing obviously. After oxygen plasma etching, the electric conductivity was increased for lightly doped silicon nanowires.
