Pavlenko Maksim A, Tikhonov Yuri A, Razumnaya Anna G, Vinokur Valerii M, Lukyanchuk Igor A
Faculty of Physics, Southern Federal University, 344090 Rostov-on-Don, Russia.
Laboratoire de Physique de la Matière Condensée, Université de Picardie Jules Verne, 80080 Amiens, France.
Nanomaterials (Basel). 2021 Dec 28;12(1):75. doi: 10.3390/nano12010075.
It is well known that the ferroelectric layers in dielectric/ferroelectric/dielectric heterostructures harbor polarization domains resulting in the negative capacitance crucial for manufacturing energy-efficient field-effect transistors. However, the temperature behavior of the characteristic dielectric properties, and, hence, the corresponding behavior of the negative capacitance, are still poorly understood, restraining the technological progress thereof. Here we investigate the temperature-dependent properties of domain structures in the SrTiO/PbTiO/SrTiO heterostructures and demonstrate that the temperature-thickness phase diagram of the system includes the ferroelectric and paraelectric regions, which exhibit different responses to the applied electric field. Using phase-field modeling and analytical calculations we find the temperature dependence of the dielectric constant of ferroelectric layers and identify the regions of the phase diagram wherein the system demonstrates negative capacitance. We further discuss the optimal routes for implementing negative capacitance in energy-efficient ferroelectric field-effect transistors.
众所周知，介电体/铁电体/介电体异质结构中的铁电层存在极化畴，这导致了对于制造节能场效应晶体管至关重要的负电容。然而，特征介电性能的温度行为以及相应的负电容行为仍未得到充分理解，这限制了其技术进步。在此，我们研究了SrTiO₃/PbTiO₃/SrTiO₃异质结构中畴结构的温度相关特性，并证明该系统的温度-厚度相图包括铁电区和顺电区，它们对施加电场表现出不同的响应。通过相场建模和解析计算，我们发现了铁电层介电常数的温度依赖性，并确定了相图中系统表现出负电容的区域。我们进一步讨论了在节能铁电场效应晶体管中实现负电容的最佳途径。
