Abstract

The features of the interpretation of the spectral dependence of the luminescent properties of ZnO films on sapphire are presented. ZnO films of various thicknesses obtained in an oxygen atmosphere at various substrate temperatures, including the stage of recrystallization annealing, are considered for a comprehensive analysis. It is shown that, in the cathodoluminescence spectrum of thin ZnO films obtained at a low substrate temperature, only the red (650–1000 nm) band of the sapphire substrate is observed, and the luminescence of the ZnO film is suppressed by excessive defectiveness. Prolonged recrystallization annealing results in improved quality of thin ZnO films and the appearance of a wide (430–740 nm) band in ZnO. With an increase in the substrate temperature and film thickness, only the bands associated with ZnO are revealed in the cathodoluminescence spectra: an edge luminescence band (with maximum at 390 nm) and a red band (at 500–950 nm with a maximum near the region of 710 nm) associated with charged vacancies of zinc. Focusing the beam leads to local heating of the sample and an increase in the concentration of interstitial zinc. Related to this is the shift of the edge luminescence band to the 410 nm region, as well as blue mixing of the band of defect luminescence.

中文翻译：

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蓝宝石上氧化锌薄膜发光光谱的解释特征

摘要

介绍了解释ZnO薄膜在蓝宝石上的发光特性的光谱依赖性的特征。为了进行综合分析，考虑了在氧气气氛中在各种衬底温度（包括重结晶退火阶段）下获得的各种厚度的ZnO膜。结果表明，在低衬底温度下获得的ZnO薄膜的阴极发光光谱中，仅观察到蓝宝石衬底的红色（650-1000 nm）谱带，并且过大的缺陷抑制了ZnO膜的发光。长时间的再结晶退火可改善ZnO薄膜的质量，并在ZnO中出现宽（430-740 nm）的谱带。随着基板温度和膜厚的增加，阴极发光光谱中仅揭示了与ZnO相关的谱带：边缘发光谱带（最大值在390 nm）和红色谱带（在500–950 nm处，最大在710 nm区域附近）与带电的锌空位相关。聚焦光束会导致样品局部发热，并增加间隙锌的浓度。与此相关的是边缘发光带向410 nm区域的移动，以及缺陷发光带的蓝色混合。