Cho Bomin, Baek Sangsoo, Woo Hee-Gweon, Sohn Honglae
J Nanosci Nanotechnol. 2014 Aug;14(8):5868-72. doi: 10.1166/jnn.2014.8297.
Quantum efficiencies of Si quantum dots (QDs) have been investigated from the reaction of magnesium silicide and ammonium chloride. The change of quantum yield and optical characterization of Si QDs are measured depending on the reaction time. Highly luminescent Si QDs were obtained as the reaction time increased. Absorption measurement indicated that the Si QDs consisted of only silicon and hydrogen atom. Optical characterizations of Si QDs were measured by UV-Vis and PL spectroscopy. The size distribution and orientation of Si QDs were measured by TEM and XRD. TEM image displays the spherical Si QDs with the size of 3-4 nm. As the reaction time increased, Si QDs grew and their emission wavelength shifted to the longer wavelength. The monotonic shift of the PL as a function of excitation wavelength resulted in the excitation of different sizes of QDs that had different optical transition energies. Photoluminescence quantum yields exceeding 60% have been achieved.
通过硅化镁与氯化铵的反应对硅量子点（QDs）的量子效率进行了研究。根据反应时间测量了硅量子点的量子产率变化和光学特性。随着反应时间的增加，获得了高发光性的硅量子点。吸收测量表明硅量子点仅由硅和氢原子组成。通过紫外可见光谱和光致发光光谱对硅量子点进行了光学特性测量。通过透射电子显微镜（TEM）和X射线衍射（XRD）测量了硅量子点的尺寸分布和取向。TEM图像显示了尺寸为3 - 4纳米的球形硅量子点。随着反应时间的增加，硅量子点生长，其发射波长向更长波长移动。光致发光（PL）随激发波长的单调变化导致了不同尺寸、具有不同光学跃迁能量的量子点被激发。已经实现了超过60%的光致发光量子产率。
