Chibirev Aleksei O, Leontyev Andrei V, Kabanov Viktor V, Mamin Rinat F
Zavoisky Physical-Technical Institute, FRC Kazan Scientific Center of RAS, 420029 Kazan, Russia.
Department for Complex Matter, Jozef Stefan Institute, 1000 Ljubljana, Slovenia.
Nanomaterials (Basel). 2022 Oct 26;12(21):3774. doi: 10.3390/nano12213774.
The study of BaSrTiO/LaMnO/BaSrTiO heterostructures on a MgO substrate with BaSrTiO ferroelectric films revealed the occurrence of a metallic character of the temperature behavior of the resistance at a temperature less than 175 K. This behavior is associated with an increased charge concentration at the interface due to a discontinuity in the ferroelectric polarization at the interface between the films. At these temperatures, the effect of negative photoconductivity is observed under uniform illumination with the light of a selected spectral composition event on the surface of the ferroelectric film. The combined exposure to green and infrared light led to an addition of the effects. As a result, a cumulative effect was observed. The effect of metallic conductivity is due to the discontinuity of ferroelectric polarization. Therefore, we explain that the partial screening of the ferroelectric polarization by photogenerated charge carriers causes a reduction in the carrier concentration at the interface. Measurements in the Kelvin mode of atomic force microscopy showed that illumination influences the surface charge concentration in a similar way; this observation confirms our hypothesis.
对具有 BaSrTiO 铁电薄膜的 MgO 衬底上的 BaSrTiO/LaMnO/BaSrTiO 异质结构的研究表明，在温度低于 175 K 时，电阻的温度行为出现金属特性。这种行为与由于薄膜之间界面处铁电极化的不连续性导致的界面电荷浓度增加有关。在这些温度下，在铁电薄膜表面用选定光谱组成的光进行均匀照射时，观察到负光电导效应。绿色和红外光的联合照射导致了效应的叠加。结果，观察到了累积效应。金属导电效应是由于铁电极化的不连续性。因此，我们解释说光生载流子对铁电极化的部分屏蔽导致界面处载流子浓度降低。开尔文模式原子力显微镜测量表明，光照以类似方式影响表面电荷浓度；这一观察结果证实了我们的假设。
