非晶氧化硅薄膜带尾发光特性  

Band Tail Photoluminescence of Amorphous SiO_x Films

作　　者：于威[1] 戴万雷[1] 王新占[1] 刘玉梅[1] 郭少刚[1] 郭亚萍[1] 路万兵[1] 傅广生[1] 

机构地区：[1]河北大学物理科学与技术学院光电信息材料重点实验室,河北保定071002

出　　处：《光学学报》2012年第7期293-298,共6页Acta Optica Sinica

基　　金：国家自然科学基金(60940020;60878040)资助课题

摘　　要：采用等离子体增强化学气相沉积技术,通过改变CO2流量制备了不同氧含量的非晶氧化硅薄膜。利用紫外可见吸收谱、傅里叶红外吸收谱和稳态/瞬态光致发光谱等技术研究了薄膜的微观结构和光学特性。实验结果表明,随着氧含量的增加,薄膜的带隙增大,光致发光强度增加、峰值朝高能方向移动、光谱半峰全宽展宽。时间分辨光谱显示薄膜发光峰值处的衰减时间随氧含量的增加从6.2ns单调增加到21ns,而同一样品的发光寿命随发射波长能量增加而减小。综合分析光学吸收、发射及发光衰减特性表明,薄膜的发光机制主要归结为非晶材料带尾态之间的辐射复合。Amorphous silicon oxide （a-SiOx） films are prepared using plasma enhanced chemical vapor deposition technique. The microstructural and optical characteristics of a-SiOx films are investigated by Fourier transformed infrared spectra, optical absorption spectra, and steady/time-resolved photoluminescence （PL） spectra. With the CO2 flow rate increasing, the band gap and PL intensity of the films increase, the PL peak moves toward high energies, and the full width at half maximum of the PL are widened. In addition, the decay time at PL peaks increases from 6.2 ns to 21 ns with oxygen content enhancing. However, linearly decreased decay time with energy increasing is found for one sample. Optical transitions among band tail states of amorphous materials are considered as the main light emission mechanism based on the analysis of optical absorption, emission and decav chzrzct^ri^tic~

关 键 词：光谱学 带尾态发光 光学吸收 时间分辨光谱 非晶氧化硅 

分 类 号：O433.4[机械工程—光学工程] O751[理学—光学]