论文部分内容阅读
采用线性组合算符法和幺正变换方法,研究极性晶体膜中束缚极化子的基态能量、自陷能随膜厚d的变化关系。得出束缚极化子的自陷能由两部分组成:第一部分是由于电子-体LO声子相互作用所引起的(Eetr-LO)极化子效应;第二部分则是电子-SO声子相互作用引起的。后者又包含两部分,分别是电子与极性膜中两支表面声子相互作用的贡献(Eetr-SO( +),Eetr-SO( -))。通过对KCl半导体膜的数值计算表明,Eetr-LO随膜厚d的增加而增加;但是Eetr-SO、极化子的振动频率以及电子-声子相互作用所产生的总自陷能Eetr-ph随膜厚d的增加而减少,当膜厚大于5 nm时,总自陷能Eetr-ph趋于一稳定值。另外,由于束缚势的存在,使极化子的振动频率增大,这主要是由于束缚势的存在,使电子-声子间的相互作用增强,极化子效应增大而引起的。
Linear combinatorial operator and unitary transformation method are used to study the ground state energy of the polaron in the polar crystal film and the dependence of the self-trapping energy with the film thickness d. It is concluded that the trap of the bound polaron can be composed of two parts: the first part is due to the (Eetr-LO) polaron effect caused by the electron-body LO phonon interaction; the second part is the electron-SO phonon Interaction caused by. The latter consists of two parts, Eetr-SO (+) and Eetr-SO (-), respectively, for the interaction of the two surface phonons in the electron and the polar film. The numerical calculation of KCl semiconductor film shows that Eetr-LO increases with the increase of film thickness d. However, the total entrapment energy Eetr-ph of Eetr-SO, the vibrational frequency of the polaron and the electron-phonon interaction With the increase of film thickness d, the total trap energy Eetr-ph tends to a stable value when the film thickness is more than 5 nm. In addition, due to the existence of the binding potential, the vibration frequency of the polaron is increased, which is mainly due to the existence of the binding potential, which results in the enhancement of the interaction between the electron and the phonon and the increase of the polaron effect.