Correlation between the photoluminescence lifetime and defect density in bulk and epitaxial ZnO
Correlation between the photoluminescence lifetime and defect density in bulk and epitaxial ZnO
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DOI：
10.1063/1.1540220
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发表时间：
2003-01-27
影响因子：
4
通讯作者：
Koinuma, H
中科院分区：
文献类型：
--
作者：
Koida, T;Chichibu, SF;Koinuma, H
利用稳态和时间分辨光致发光（PL）谱，结合正电子湮没测量结果，研究了ZnO中点缺陷对ZnO非辐射过程的影响。自由激子PL强度自然地随着非辐射PL寿命（τ（nr））的增加而增加。在ScAlMgO 4衬底上生长的异质外延薄膜中，随着生长温度的升高，Zn空位（V-Zn）的密度或尺寸减小，τ（nr）增大。使用同质外延衬底进一步降低了V-Zn密度。然而，τ（nr）对于同质外延膜是最短的;即，在τ（nr）和V-Zn或正电子散射中心的密度/尺寸之间没有发现明显的依赖性。结果表明，非辐射复合过程不仅受单点缺陷的控制，而且还受V-Zn的存在所引入的某些缺陷物种（如空位复合物）的控制。(C)2003年，美国物理学会。
Influences of point defects on the nonradiative processes in ZnO were studied using steady-state and time-resolved photoluminescence (PL) spectroscopy making a connection with the results of positron annihilation measurement. Free excitonic PL intensity naturally increased with the increase in the nonradiative PL lifetime (tau(nr)). Density or size of Zn vacancies (V-Zn) decreased and tau(nr) increased with increasing growth temperature in heteroepitaxial films grown on a ScAlMgO4 substrate. Use of homoepitaxial substrate further decreased the V-Zn density. However, tau(nr) was the shortest for the homoepitaxial film; i.e., no clear dependence was found between tau(nr) and density / size of V-Zn or positron scattering centers. The results indicated that nonradiative recombination processes are not solely governed by single point defects, but by certain defect species introduced by the presence of V-Zn such as vacancy complexes. (C) 2003 American Institute of Physics.