镁掺杂对二氧化钒薄膜光学性能的影响  

Effect of Mg-doping on the Optical Properties of Vanadium Dioxide

作　　者：赵鑫 康同同 梁潇[2,3,5] 邬春阳 周阳 秦俊[2,3] ZHAO Xin;KANG Tongtong;LIANG Xiao;WU Chunyang;ZHOU Yang;QIN Jun(State Key Laboratory of High Power Semiconductor Lasers,Changchun University of Science and Technology,Changchun 130022,China;National Engineering Research Center of Electromagnetic Radiation Control Materials,University of Electronic Science and Technology of China,Chengdu 610054,China;Key Laboratory of Multi-spectral Absorbing Materials and Structures of the Ministry of Education,University of Electronic Science and Technology of China,Chengdu 611731,China;Research Center on Vector Optical Fields,Institute of Optics and Electronics,Chinese Academy of Sciences,Chengdu 610209,China;Information Materials and Device Applications Key Laboratory of Sichuan Provincial Universities,Chengdu University of Information Technology,Chengdu 610225,China)

机构地区：[1]长春理工大学高功率半导体激光器国家重点实验室,长春130022 [2]电子科技大学国家电磁辐射控制材料工程技术研究中心,成都610054 [3]电子科技大学多频谱吸收材料与结构教育部重点实验室,成都611731 [4]中国科学院光电技术研究所矢量光场研究中心,成都610209 [5]成都信息工程大学四川省信息材料与器件应用重点实验室,成都610225

出　　处：《表面技术》2024年第20期183-189,222,共8页Surface Technology

基　　金：中华人民共和国科学技术部(2021YFB2801600);国家自然科学基金(U22A20148,51972044,52021001,52102357,51902033,52001059);四川省科学技术厅(2024NSFSC0484);中国博士后科学基金(M202068328);成都信息工程大学科学研究基金(KYTZ202006)。

摘　　要：目的通过在二氧化钒薄膜中掺杂镁元素,实现高优值光学相变材料的制备。方法通过脉冲激光沉积方法在(0001)氧化铝单晶衬底上沉积二氧化钒外延薄膜,进一步采用交叉打靶的方法沉积不同镁掺杂浓度的二氧化钒外延薄膜;通过高分辨XRD和TEM表征镁掺杂外延二氧化钒薄膜的晶体结构和微观原子分布,采用XPS表征表面原子化学态,采用光谱椭偏仪表征不同镁掺杂浓度的二氧化钒外延薄膜的折射率和消光系数,并计算获得光学优值;最后构建第一性原理计算模型得到镁掺杂对二氧化钒薄膜光学优值影响的机理。结果制备出4种不同镁掺杂浓度的外延二氧化钒薄膜,分析了镁掺杂对薄膜相变前后的晶体取向和微观原子结构的影响,分析了薄膜中镁和钒元素的价态,分析了镁掺杂对单斜相和金红石相光学常数和光学优值的影响,从电子态密度分布分析了镁掺杂对提升材料光学优值的原因。结论镁掺杂二氧化钒与氧化铝衬底的外延关系为(020)_(VO_(2))//(0006)_(Al_(2)O_(3)),随着镁掺杂浓度的提高,金红石相二氧化钒薄膜的光学损耗降低,且中红外波段的光学优值提升。在11.9%(原子数分数)掺杂量时光学优值比未掺杂提高3.7倍。第一性原理计算表明,高光学优值是源于镁掺杂后导带周围电子态密度的局部化。Vanadium dioxide(VO_(2))is a promising optical phase change material for tunable photonic devices showing large optical contrast,low power consumption and ultrafast modulation.However,the rutile phase of VO_(2) has excessive optical loss due to the free carrier absorption,limiting its performance in photonics devices.The work aims to demonstrate low loss and high figure of merit in epitaxial VO_(2) films on c-cut sapphire substrates by Mg^(2+)doping.The Mg^(2+)doping can heavily reduce the optical loss in rutile phase,and improve the FOM at mid-infrared wavelength.The epitaxial VO_(2) films were deposited on c-cut sapphire substrates by pulse laser deposition method.Furthermore,the VO_(2) epitaxial films with different Mg doping concentrations were deposited by correlative adjustment of the duty-cycle and deposition time.The crystalline structures of Mg-doped VO_(2) films at different temperatures were confirmed by high-resolution X-ray diffraction(XRD).The surface chemical states of Mg-doped VO_(2) films were measured by X-ray photoelectron spectroscopy(XPS).The concentrations of Mg doping were measured by inductively coupled plasma optical emission spectrometry(ICP-OES).To understand the atomic configurations of the Mg-doped VO_(2),the cross-section TEM image and selected area electron diffraction(SAED)pattern were studied by TEM.For optical properties,the Mg-doped VO_(2) films were measured by spectroscopic ellipsometry.Finally,the first-principles calculations were used to understand the physical mechanism of the improvement of FOM by Mg doping.Four Mg-doped VO_(2) films with concentrations 0%,5.6%,8.6%and 11.9%were successfully deposited.All the films presented well out-of-plane epitaxial relationship to Al_(2)O_(3) substrate with(020)VO_(2)//(0006)Al_(2)O_(3).At low doping levels,the Mg-doped VO_(2) films indicated obvious phase transition process with monoclinic(020)M transforming into metallic rutile(020)R from analysis of XRD spectra.However,the 11.9%Mg-doped VO_(2) presented no XRD peak shift,demonstrat

关 键 词：二氧化钒 相变材料 镁掺杂 光学优值 脉冲激光沉积 

分 类 号：TB34[一般工业技术—材料科学与工程]