氮掺杂碲化锗薄膜晶体结构及电子能带研究  

CRYSTAL STRUCTURE AND ELECTRONIC BAND OF NITROGEN DOPED GERMANIUM TELLURIDE THIN FILMS

作　　者：郭爽 王运锋 崔少博 GUO Shuang;WANG Yun-feng;CUI Shao-bo(School of Information Engineering,Nanyang Institute of Technology,Nanyang 473004,China)

机构地区：[1]南阳理工学院信息工程学院,河南南阳473004

出　　处：《南阳理工学院学报》2023年第4期61-65,共5页Journal of Nanyang Institute of Technology

基　　金：国家自然科学基金项目(52102194);河南省科技攻关项目(212102210115);南阳理工学院2021年课程思政示范课建设项目(NIT2021KCSZ-40)。

摘　　要：研究了氮掺杂对碲化锗(GeTe)薄膜晶体结构、光学带隙和带尾局域态的影响。氮掺杂提高了GeTe的结晶温度和薄膜电阻。随着氮掺杂浓度的增加,薄膜材料表面变得更加致密和光滑,从而具有更好的电学性能和更小的残余应力。拉曼散射光谱分析了氮掺杂GeTe材料的局域键结构。透射光谱反映了薄膜光学带隙和电子局域态密度的变化。氮掺杂后带隙的展宽对于降低相变存储器的阈值电流是至关重要的。随着氮掺杂浓度的提高,非晶态薄膜透射光谱B1/2和U的斜率值单调递减分别对应于原子构型随机性的增加和带尾局域态的增大。反之,晶态薄膜透射光谱B1/2和U斜率值增加分别对应于材料结构有序度的增加和带尾局域态的减小。The nitrogen doping effect on crystal structure,optical band gap,and localized states for GeTe films was studied.The crystallization temperature and sheet resistance were improved by nitrogen doping.The film surfaces become more compact and smooth with increasing nitrogen concentration,which contributes to generating a better electrical behavior and smaller residual stress.Raman spectra elucidate the local bonding structure of amorphous and crystalline nitrogen doped GeTe(Nx(GeTe)1-x).Transmittance spectra evaluate the changes in optical band gap and localized states density for the films.The band gap broadening after nitrogen doping is crucial to reducing the threshold current for phase change memory.The slope reduction of B1/2 and U by N doping can be related to the increment of randomness in atomic configuration and the augmentation of band-tail localized states,respectively.Conversely,the increment of that for crystalline films corresponds to the order degree increasement and band-tail localized states diminution,respectively.

关 键 词：氮掺杂 相变 晶体结构 光学带宽 

分 类 号：O469[理学—凝聚态物理]