中文摘要：

考虑1-3型垂直异质铁电P（VDF-TrFE）基复合薄膜结构,利用非线性的热力学理论分析和讨论了平面外应变对复合薄膜电热性能的调控作用.结果表明,在施加的垂直电场下,平面外应变可以有效地调控电极化、热释电系数、绝热温差等铁电、电热性能.通过合理的调控平面外应变可以在很大的温度区域范围内获得比纯平面外延薄膜结构更高的绝热温差.研究结果预示着垂直异质P（VDF-TrFE）基复合薄膜结构在一定的工作温度范围内具有优异的电热性能,在微电源、光通信二极管、红外传感器等微型元件方面有着广泛的应用前景.

英文摘要：

Considering the boundary conditions of 1-3-type P（VDF-TrFE） composite ferroelectric film, the effect of out-of-plane strain on the electrocaloric performances of vertical heteroepitaxial film is calculated by the nonlinear thermodynamic theory. The results indicate that the out-of-plane strain can effectively regulate the ferroelectric and electrocaloric performances including the polarization, electrocaloric coefficient and adiabatic temperature change under the action of vertical electric field. In a wide temperature range, the vertical heteroepitaxial film can present higher adiabatic temperature change than the pure P（VDF-TrFE） film by controlling the out- of-plane strain. This indicates that the vertical composite heteroepitaxial film with excellent electrocaloric performances will have potential applications in the microelectronic devices such as micropowers, optical communication diodes and infrared sensors.