论文部分内容阅读
采用3ω方法在100~320K温度范围内测试了不同周期长度的InGaAs/InGaAsP超晶格薄膜的导热系数.结果表明对于周期性超晶格结构,随着温度的升高,热传导能力下降;比较周期长度不同的超晶格结构的测试结果,发现导热系数会随着周期长度的增大而减小,并在某一周期长度取得最小值,但随着周期长度的进一步增大,导热系数又出现上升趋势,表明在长周期超晶格结构中界面热阻是影响声子传输的主要因素.理论计算表明,对于短周期的超晶格结构,Bragg反射是造成产生最小值的原因之一,由于声子穿透率的下降,造成导热系数随着周期长度的增大而减小.理论与实验研究结果表明,随着周期长度的增大,声子的传输规律由声子的波动性过渡到粒子性,这对实现声子的剪裁具有重要意义,为设计超晶格结构提供理论基础.
The thermal conductivities of InGaAs / InGaAsP superlattice films with different period lengths were tested by 3ω method in the temperature range of 100 ~ 320 K. The results show that for the periodic superlattice structure, the thermal conductivity decreases as the temperature increases; Length of the different superlattice structure test results and found that the thermal conductivity will decrease with the increase of the length of the cycle, and to obtain the minimum length of a certain period, but with the further increase in the length of the cycle, the thermal conductivity again Which indicates that the interface thermal resistance is the main factor affecting the phonon transmission in the long-period superlattice structure.Theoretical calculations show that Bragg reflection is one of the reasons for the minimum value for the short-period superlattice structure, The decrease of phonon transmittance leads to the decrease of thermal conductivity with the increase of the period length.Theoretical and experimental results show that with the increase of the length of the period, the phonon transmission rule changes from phonon fluctuation to Particle, which is of great significance for the phonon clipping, and provides a theoretical basis for the design of the superlattice structure.