掺磷nc-Si∶H薄膜的微结构与光电特性  

Study on Microstructure and Optoelectrical Properties of Phosphorus Doped nc-Si∶H Thin Films

作　　者：刘利[1] 马蕾[1,2,3] 吴一[1] 范志东[1] 郑树凯[1,2,3] 刘磊[1,2,3] 彭英才[1] 

机构地区：[1]河北大学电子信息工程学院,保定071002 [2]河北大学计算材料研究中心,保定071002 [3]河北大学医工交叉研究中心,保定071002

出　　处：《人工晶体学报》2015年第10期2756-2761,共6页Journal of Synthetic Crystals

基　　金：国家自然科学基金青年科学基金(61204079);河北省自然科学基金(E2012201088;F2013201196);河北省高等学校科学技术研究项目(2011237;ZH2012019);河北省青年拔尖人才计划(2013)

摘　　要：采用常规射频等离子体增强化学气相沉积方法,以高氢稀释的Si H4为源气体和以PH3为掺杂剂,制备了磷掺杂的氢化纳米晶硅薄膜。结果表明,薄膜的生长速率随PH3/Si H4流量比（Cp）增加而显著减小。Raman谱的研究证实,随Cp增加,薄膜的晶化率经历了先增大后减小的过程,当Cp=1.0%,晶化率达到最大值45.9%。傅里叶变换红外吸收谱测量结果显示,薄膜中的H含量在Cp=2.0%时达到最低值9.5%。光学测量结果表明,本征和掺P的氢化纳米晶硅薄膜在可见光谱范围呈现出良好的光吸收特性,在0.8~3.0 e V范围内,nc-Si（P）∶H薄膜的吸收系数显著大于c-Si。和α-Si∶H薄膜相比,虽然短波范围的吸收系数较低,但是在hν〈1.7 e V区域,nc-Si（P）∶H薄膜的吸收系数要高两到三个量级,显示出优良的红光响应。电学测量表明,适当掺P会显著提高氢化纳米晶硅薄膜的暗电导率,当Cp=0.5%时,薄膜的暗电导率可达5.4 S·cm-1。The phosphorus doped hydrogenated nanocrystalline silicon thin films were prepared, using high hydrogen dilution silane as reaction gas source and phosphine as dopant gas source in a conventional radio frequency plasma enhanced chemical vapor deposition system. The results show that the growth rate of the films decreases significantly as PH3/SiH4 flow ratio （ Cp ） increasing. The study of Raman spectra confirmed that the crystallization rate of the thin films increases first and then decreases as Cp increasing, and the crystallization rate reaches the maximum of 45.9% when Co = 1.0%. Fourier transform infi＇ared absorption spectrum measurement results show that the H content in the films reached the lowest value 9. 5% at Cp = 2. 0%. Optical measurements show that the intrinsic and P doped hydrogenated nanocrystalline silicon thin films exhibit good optical absorption properties, in the range of 0.8-3.0 eV. The absorption coefficient of nc-Si （P） ： H thin films is significantly higher than that of c-Si materials. Compared with the α-Si： H thin films, although the absorption coefficient is lower in short wave range, the absorption coefficient of nc-Si（P） ： H films is two to three orders of magnitude than α-Si： H thin films in hv 〈 1. 7 eV area. Electrical measurements show that the P can significantly improve the dark conductivity of hydrogenated nanocrystalline silicon thin films, and the dark conductivity of the films can reach up to 5.4 S · cm-1 as Cp =0.5%.

关 键 词：磷掺杂氢化纳米晶硅薄膜 晶化率 界面体积分数 光吸收系数 暗电导率 

分 类 号：O484[理学—固体物理]