摘要
本文主要对超声喷雾热解方法生长在本征Si衬底上的N-In共掺的p型ZnO薄膜的Raman光谱进行了研究。通过洛仑兹(Lorentz)模型和等离子激元与纵光学声子耦合模理论模型拟合不同浓度下的室温Raman光谱,我们对样品的Raman峰进行了指认;同时也得到了样品的空穴浓度和迁移率,结果和霍耳测量得到的空穴浓度和迁移率符合的较好,证明了霍耳测量p型ZnO薄膜得到的电学参数是可信的。随后我们又对不同浓度的p型ZnO薄膜的变温Raman光谱进行研究,运用一个详细的模型(考虑了晶格热膨胀、残余应力、和三声子、四声子衰变)描述不同浓度下各个样品Raman光谱中的等离子激元与纵光学声子耦合模随温度变化的情况。分析拟合参数,可以清楚地了解随着浓度的增加耦合模参数随温度的衰变行为。
This paper concentrates on the Raman optical properties of N-In codoped p-type ZnO thin films grown by ultrasonic spray pyrolysis. We have studied the room temperature of Roman spectra of p-type ZnO thin films with different hole densities combining the Lorentzian mode and the coupled LO phonon-plasmon mode （CPPM） theory. Three phonon modes are identified and the hole density and mobility have been deduced from the Raman lineshape analysis using the CPPM theory. The good agreement between the Roman and Hall results provides us confidence in the reliability of the carrier transport parameters determined from the Hall measurements in the p-ZnO thin films. As for the temperature dependence of Raman spectroscopy of p-type ZnO thin films, the CPPMs can be well described by a model which has taken into account the contributions of the thermal expansion of the crystal lattice, the strain between p-type ZnO thin films and Si substrates, as well as three- and four-phonon decay. Our results clearly show the anharmonic decay of CPPMs in p-type ZnO thin films with increasing temperature and increasing hole density
出处
《光散射学报》
北大核心
2009年第1期29-36,共8页
The Journal of Light Scattering
基金
国家自然科学基金重点项目(10734020)
