室温下Pr_(0.7)Ca_(0.3)MnO_3薄膜的瞬态光响应特性  

Transient photoresponse in Pr_(0.7) Ca_(0.3) MnO_3 thin films at room temperature

作　　者：严资杰[1] 袁孝[1] 徐业彬[1] 高国棉[2] 陈长乐[2] 

机构地区：[1]华中科技大学光电子科学与工程学院,武汉430074 [2]西北工业大学理学院,西安710072

出　　处：《物理学报》2007年第10期6080-6083,共4页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:60171034;10476010;10676010)资助的课题~~

摘　　要：在室温下利用波长532nm,脉冲宽度7ns的纳秒脉冲激光研究了不同电压和激光能量密度作用下Pr0.7Ca0.3MnO3薄膜的瞬态光响应特性.在激光能量密度为275.16mJ/cm2时,其最大电阻变化率达到92.3%,响应时间约36ns.室温下电压变化对薄膜的光响应特性影响不大,而诱导光能量密度的影响则很明显,能量密度越大,电阻变化越大,响应时间越短,并且电阻变化和响应时间均与激光能量密度呈非线性关系.这种光响应来源于薄膜中的光致非稳态绝缘体-金属相变,有望在新型光电器件上获得应用.Photoresponse characteristics of Pr0.7Ca0.3MnO3 thin films were investigated under different applied voltages and excitation light energy densities at room temperature. The transient resistance change of 92.3 % and response time of - 36 ns were observed under the excitation with a 532 nm laser pulse of 7 ns duration at a light energy density of 275.16 mJ/cm^2 . Both the resistance change and response time showed nonlinear behavior as a function of the light energy density, and the resistance and the response time were reduced when the intensity increased. However, the applied voltage had almost no effect on the photoresponse at room temperature. The phenomena are explained in terms of the photoinduced nonequilibrium insulator-to-metal transition in the film, which may have potential applications in optoelectronic devices.

关 键 词：光响应 钙钛矿薄膜 绝缘体-金属相变 

分 类 号：O484[理学—固体物理]