Influence of paramagnetic defects on multicolored luminescence from nanocrystalline silicon
Influence of paramagnetic defects on multicolored luminescence from nanocrystalline silicon
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DOI：
10.1063/1.2399933
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发表时间：
2006-12-01
影响因子：
3.2
通讯作者：
Hirakuri, Kenji
中科院分区：
文献类型：
--
作者：
Sato, Keisuke;Hirakuri, Kenji
我们利用电子自旋共振 (ESR) 和光致发光测量报告了顺磁缺陷与纳米晶硅 (nc-Si) 发光特性之间的相关性。粒径为1.9至3.0 nm的纳米晶硅表现出从蓝色到红色波长的连续发光。然而，随着发光颜色向蓝色转变，NC-Si的密度降低。红/绿/蓝发光NC-Si包含三种ESR中心、两个非辐射复合中心（a中心和P-b中心）和辐射复合中心（P-ce'中心）。 a、P-b 和 P-ce' 中心分别源自 nc-Si 中的 Si 悬挂键、nc-Si/二氧化硅 (SiO2) 界面区域中的 Si 悬挂键以及在 nc-Si 表面附近导带边缘附近捕获的局域态电子。 P-b 和 P-ce' 中心的自旋密度随着发光颜色的蓝移而增加。增加 P-b 中心的自旋密度并降低 nc-Si 的密度导致从红色到蓝色发光的强度降低。这些结果表明，随着发射向蓝色移动，强度降低是由于单个颗粒中存在许多 P-b 中心以及产生了少量密度的 nc-Si。 (c) 2006 年美国物理研究所。
We report on the correlation between paramagnetic defects and the luminescent properties of nanocrystalline silicon (nc-Si) using electron spin resonance (ESR) and photoluminescence measurements. Nanocrystalline silicon having particle sizes from 1.9 to 3.0 nm exhibited continuous luminescence from blue to red wavelengths. However, the density of nc-Si decreased as the luminescent color was shifted towards blue. Red/green/blue luminescent nc-Si contained three kinds of ESR centers, two nonradiative recombination centers (an a center and a P-b center), and a radiative recombination center (a P-ce' center). The a, P-b, and P-ce' centers originate from a Si dangling bond in nc-Si, a Si dangling bond in the nc-Si/silicon dioxide (SiO2) interface region, and electrons trapped in localized states close to the conduction band edge in the vicinity of the nc-Si surface, respectively. The spin densities of the P-b and P-ce' centers increased with the blueshift of the luminescent color. Increasing the spin density of the P-b center and reducing the density of nc-Si led to a reduction in the intensity from the red to the blue luminescence. These results indicate that this reduction in intensity as the emission was shifted towards blue was due to the presence of many P-b centers in a single particle and the generation of a little density of nc-Si. (c) 2006 American Institute of Physics.