摘要
用X射线光电子能谱和同步辐射光电子能谱研究了Sb掺杂的钙钛矿型氧化物SrTi1 -xSbxO3(x =0 .0 5 ,0 .10 ,0 .15 ,0 .2 0 )薄膜的电子结构 .薄膜由紫外脉冲激光淀积在SrTiO3( 0 0 1)单晶衬底上 .该薄膜系列在可见光波段透明 ,透过率均超过 90 % .其导电性与掺杂浓度有关 ,当Sb掺杂浓度x =0 .0 5时 ,薄膜显示金属型导电性 .X射线光电子能谱和同步辐射光电子能谱研究结果表明 ,Sb掺杂在母化合物SrTiO3的禁带内引入了浅杂质能级和深杂质能级 .浅杂质能级上的退局域化电子离化到导带中会产生一定的传导电子 ,这是SrTi0 .95Sb0 .0 5O3薄膜金属型导电性的起源 .杂质带与导带中低的电子态密度限制了跃迁概率和光吸收 .大的禁带宽度 ,小的跃迁概率和弱的光吸收 。
Optically transparent Sb-doped SrTiO3 (SrTi1-xSbxO3) thin films with a transmittance higher than 90% in visible region have been grown on SrTiO3 (001) substrates by pulsed laser deposition method using an XeCl laser under oxygen partial pressure of 20 Pa. The thin film with Sb doping concentration of x = 0.05 shows metallic-like conductivity with a resistivity rho similar to 6.99 x 10(-3)Ohm(.)cm at room temperature. XPS and synchrotron radiation photoelectron spectroscopy (SR-PES) measurement from the SrTi0.95Sb0.05O3 thin film reveals that the shallow and deep impurity donor levels within the band gap of the parent compound SrTiO3 are induced by the Sb doping. The delocalized electrons within the shallow levels near the Fermi level can be excited to the conduction band as free carriers for electrical conduction by thermal ionization. The wide band gap, small transition probability and weak absorption due to the low density of states in the impurity levels result in the optical transparency of the film.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2002年第1期187-191,共5页
Acta Physica Sinica
基金
国家自然科学基金重点项目 (批准号 :5 9832 0 5 0 )
国家重点基础研究计划项目资助的课题~~
