上电极对镧镍共掺铁酸铋薄膜电学性质的影响

Effect of Top Electrode on Electric Properties of La and Ni Co-doped BiFeO3 Thin Films

采用溶胶？凝胶法在Pt（111）/Ti/SiO2/Si（001）基片上制备了La和Ni共掺的多晶Bi0.975La0.025Fe0.975Ni0.025O3（BLFNO）薄膜,分别以氧化铟锡（ITO）和Pt/Sr Ru O3（SRO）为上电极构建了ITO/BLFNO/Pt和SRO/BLFNO/Pt两种电容器。研究了两种上电极对BLFNO薄膜电学性质的影响。当测试电场为1 333 kV/cm时,ITO/BLFNO/Pt和SRO/BLFNO/Pt电容器的剩余极化强度分别为105和139μC/cm2。通过拟合两种电容器的电流密度,发现导电机理都为Poole-Frankel机制。当404 nm的紫光入射到两种电容器表面,电流密度都相应的增大。测试电场为250 kV/cm时,ITO/BLFNO/Pt电容器电流密度增长量为6.55×10？4 A/cm2;而SRO/BLFNO/Pt电容器的增长量为1.38×10？4 A/cm2。

A thin film of polycrystalline La and Ni co-doped Bi0.975La0.025Fe0.975Ni0.025O3（BLFNO）was deposited on Pt（111）/Ti/SiO2/Si（001）substrate by a sol-gel method.Two capacitors of ITO/BLFNO/Pt and SrRuO3（SRO）/BLFNO/Pt were constructed.The remanent polarizations of ITO/BLFNO/Pt and SRO/BLFNO/Pt capacitors measured at 1 333 kV/cm are 105 and139μC/cm2,respectively.The Poole-Frank conduction behavior is a dominated leakage mechanism of both capacitors.The leakage current density of both capacitors increases when exposed to a purple light of 404 nm.The increase of current density of ITO/BLFNO/Pt capacitor is larger than that of SRO/BLFNO/Pt capacitor when the testing electric field is 250 kV/cm.