La1－xSrxMnO3/TiO2 (x=0.2, 0.15, 0.04)异质pn结的整流特性

采用磁控溅射法制备的La_1-xSr_xMnO₃ (LSMO)/TiO₂异质pn结表现出很好的整流特性.室温电流电压特性曲线显示随着Sr掺杂的增加，扩散电压增大，这可能由于Sr掺杂的增加导致载流子浓度增大所致.电流电压变温特性曲线显示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界面电子结构的变化所致.值得提出的，异质pn结电阻随温度变化曲线表现出单层LSMO的金属绝缘相变特性，并且在低测量温度时表现出随着测量温度的降低结电阻增大，这可能是由于宽带隙的TiO₂的引入导致.关键词：异质结整流特性庞磁阻

Rectifying characteristics of La1-xSrxMnO3/TiO2(x=0.2,0.15,0.04) pn heterojunctions

La_1-xSr_xMnO₃(LSMO)/TiO₂ pn heterojunctions have been successfully synthesized by RF magnetron sputtering and they exhibit good rectifying properties. The diffusion potentials increase with increasing Sr concentration, which may be attributed to the increased carrier concentration. And the diffusion potential increases with decreasing measurement temperature, which may have resulted from modification of the interface electronic structure of La_1-xSr_xMnO₃/TiO₂ pn heterojunction with changing temperatures. It is worth noting that the metal-insulator (M-I) transition of LSMO can also be observed in pn heterojunctions and the increased sheet-resistance of pn heterojunctions at low temperature is related to the introduction of TiO₂.