非晶硅磷合金红外及光学性质研究

Study of IR and Optical Properties of Amorphous Silicon-Phosphorus Alloy Films

本实验采用辉光放电法制备出 a-SiP∶H 合金薄膜。用光电子能谱、电子衍射、红外光谱以及密度测试确定了合金的组成和结构。在分析了测试结果的基础上总结出:在非晶硅网络中,加入第二种合金组元 P 以后,键强及化学、结构有序度的变化对非晶合金的扩展态及带尾态起着决定作用,从而定性地解释了非晶合金光能隙、光学常数随成份的变化规律。

Electron diffraction,infrared spectra,XPS and density of a-SiP:H alloy filmsprepared by rf glow discharge decomposition of SiH_4-PH_3 mixtures have been mea-sured.Based on the analysis of above measurements,we have concluded that thevariation of bond strength and locally chemical and structural order in the amor-phous silicon matrix,when adding the second alloy element,phosphorus,in thesystem,has a definitive influence upon the localized tail states and extented bandstates.Finally,we have explained the dependence of refractive index and opticalgap on compositions of the alloys.