Structural changes and hydrogen motion in a-Si:H observed by proton NMR
Structural changes and hydrogen motion in a-Si:H observed by proton NMR
复制标题
质子 NMR 观察 a-Si:H 中的结构变化和氢运动
DOI：
--
复制
发表时间：
1999
期刊：
影响因子：
--
通讯作者：
Yue Wu
中科院分区：
文献类型：
--
作者：
J. Baugh;D. Han;Qi Wang;Yue Wu
利用质子核磁共振（NMR）研究了a-Si：H中氢的动力学和微观结构。除了在所有a-Si：H中观察到的一般宽线和窄线之外，随着温度升高到RT以上，观察到另外的窄线（约1 kHz宽）。相对于宽度为几kHz的一般窄线，该窄线向高场偏移约4 ppm。在150 ℃以下，质子光谱随温度的变化是可逆的;与这条额外的窄线相关的氢被证明来自最初与宽线相关的氢。这种上场位移窄线的自旋-晶格弛豫时间T{sub 1}约为0.4 s。这个短T{sub 1}，沿着它的小线宽，表明这条线与分子氢有关，可能被困在原子尺寸的位置。
Proton nuclear magnetic resonance (NMR) is applied to investigate hydrogen dynamics and microstructures in a-Si:H. In addition to the generic broad and narrow lines observed in all a-Si:H, an additional narrow line (about 1 kHz wide) is observed as the temperature is raised above RT. This narrow line is shifted to the up-field by about 4 ppm with respect to the generic narrow line of a few kHz in width. Below 150 C, the change of the proton spectrum with temperature is reversible; the hydrogen associated with this additional narrow line is shown to originate from hydrogen originally associated with the broad line. The spin-lattice relaxation time T{sub 1} of this up-field shifted narrow line is about 0.4 s. This short T{sub 1}, along with its small linewidth, suggests that this line is associated with molecular hydrogen, possibly trapped in sites of atomic dimensions.