脉冲激光沉积制备SrSn_(1-x)Co_xO_3外延薄膜的微结构表征及能带调控(英文)  

Microstructure and Band Gap Modulation of SrSn_(1-x)Co_xO_3 Epitaxial Thin Films via Pulsed Laser Deposition

作　　者：虎学梅 高相东[2] 李效民[2] 顾正莹 施鹰[1] 吴永庆[2] 

机构地区：[1]上海大学材料科学与工程学院,上海200444 [2]中国科学院上海硅酸盐研究所,高性能陶瓷与超微结构国家重点实验室,上海200050

出　　处：《物理化学学报》2016年第4期828-833,共6页Acta Physico-Chimica Sinica

基　　金：supported by the National Natural Science Foundation of China(51572281,61204073);Basic Research Foundation of Shanghai,China(13NM1402101)~~

摘　　要：钙钛矿结构SrSnO3因其独特的介电和半导体性质而备受关注,通过掺杂可显著调控其电学、磁学性能,拓宽其应用范围。本研究在单晶SrTiO3（001）衬底上通过脉冲激光方法外延生长了SrSn1-xCoxO3（x=0,0.16,0.33,0.5）（SSCO）薄膜,探究了Co含量对薄膜结晶性、微观结构、光学性能以及介电性能的影响。结果表明,SrSn1-xCoxO3薄膜可在Sr Ti O3（001）衬底上外延生长,Co掺杂不会导致薄膜结晶质量的劣化。薄膜表面形貌平整、致密,膜厚200 nm,表面粗糙度为0.44 nm。随薄膜中Co掺杂量增加,薄膜透过率从90%降至25%,光学带隙从4.24 e V降至2.44 e V。介电性能测试表明,掺杂薄膜在106Hz时介电常数为70.1,比无掺杂SrSnO3薄膜提高57%。室温时SSCO薄膜表面电阻率为172 MΩ,在1000℃范围内薄膜结构稳定。Perovskite-structured SrSnO3 has attracted considerable attention in recent years because of its unusual dielectric and semiconducting properties. Certain dopants can be used to modify and improve the properties of these materials. Epitaxial SrSn1-xCoxO3（x = 0, 0.16, 0.33, 0.5）（SSCO） thin films were deposited on single crystal SrTiO3（001） substrates via the pulsed laser deposition method. The crystallinity, microstructure,optical, and electrical properties of the films were investigated. The results indicated that SrSn1-xCoxO3 films were epitaxially grown on SrTiO3（001） substrate with both a perovskite structure and high crystallinity irrespective of the Co doping level. The films exhibited a smooth and dense morphology with a root-mean-square roughness of 0.44 nm and a film thickness of ～200 nm. As the‘x’value increased from 0 to 0.5, the optical transmittance decreased from 90% to 25%, and the band gap dropped from 4.24 to 2.44 eV. Moreover, the doped film exhibited a high dielectric constant of 70.1 at 106 Hz, 57% higher than the control SrSnO3 film. The SSCO film displayed surface resistivity of 172 MΩ at room temperature and high stability at temperature up to 1000 ℃

关 键 词：碱土锡酸盐 物理气相沉积 薄膜 外延生长 光学带隙 

分 类 号：TB383.2[一般工业技术—材料科学与工程]