摘要
采用磁控溅射法在Si衬底上通过改变沉积顺序制备两类异质PN结:La0.8Sr0.2MnO3/TiO2和TiO2/La0.8Sr0.2MnO3,并对其进行电学性能研究。结果显示Si/La0.8Sr0.2MnO3/TiO2异质PN结中的I-V特性曲线呈现线性特征。这可能是TiO2薄膜区内垂直于生长界面的缺陷使得在垂直于衬底方向上产生载流子"通道",从而导致没有整流特性。而在Si/TiO2/La0.8Sr0.2MnO3异质PN结中的I-V特性曲线却呈现良好的整流特性。这可能是La0.8Sr0.2MnO3和TiO2生长的均很致密,没有给电流提供导通通道,使得呈现明显整流特性。变温电流电压特性曲线显示整流特性出现在一个50 K到350 K广泛温区,与此同时,随着测量温度的降低,扩散电压增大,这可能由于随着测量温度的变化导致了界面电子结构的变化。
La0.8Sr0.2MnO3/TiO2 and TiO2/La0.8Sr0.2MnO3 PN heterojunctions are synthesized on Si substrates by RF magnetron sputtering through changing depositional sequence. The result shows that the I-V curves of La0.8Sr0.2MnO3/TiO2 PN heterojunetions show linear I-V characteristics. Defects particular to growth interface in the TiO2 thin film offer lots of ＂channels＂ particular to substrates for carriers, which results in linear current voltage properties. However, excellent rectifying property appears in Si/TiO2/La0.8Sr0.2MnO3 PN heterojunctions, where TiO2 films and La0.8Sr0.2MnO3 films have dense structure and can＇t offer conductive channels. Excellent rectifying properties of LSMO/TiO2 PN heterojunctions when changing measurement temperature appear in the large temperature region from 50 K to 350 K. Moreover, the diffusion potential of PN heterojunctions decreases with increasing temperatures, which is attributed to modulate the interface electronic structure of LSMO/TiO2 PN heterojunetion while changing temperature.
出处
《天津工程师范学院学报》
2009年第3期6-9,共4页
Journal of Tianji University of Technology and Education
基金
天津工程师范学院科研启动基金(KYQD07002)
关键词
异质结
整流特性
庞磁阻
heterojunction
rectifying property
colossal magneto resistance
