In this work, it is theoretically investigated that interfacial polarization electric (IPE) field of GaN/In_xGa_1-xN superlattice (SL) can be exploited for further reduction of thermal conductivity (k). IPE field modifies SL's elastic constant and phonon velocity as a result of inverse piezoelectric effect. This enhances interfacial scattering and thermal boundary resistance due to unequal changes in specific heat and phonon velocity leading to decreased phonon transmission and more mismatches of acoustic properties causing reduction in in-plane (k_ip) and cross-plane (k_cp) thermal conductivities. Room temperature k_ip in the presence (absence) of IPE field of GaN(10 nm)/In_xGa_1-xN(5 nm) SL are 7.807(8.921), 7.350(8.355), 7.018(8.090), 8.204(9.402) and 9.312(10.564) Wm⁻¹K⁻¹ respectively, for x = 0.1, 0.3, 0.5, 0.7 and 0.9; whereas k_cp for the same x are 4.652(5.710), 4.282(5.221), 4.081(5.185), 4.871(6.012) and 6.083(7.327) Wm⁻¹K⁻¹ demonstrating more than 20% reduction. It reveals that desired k can be achieved by tailoring electric field of nitride SL for better thermoelectric improvements.

在这项工作中，理论上研究了可以利用GaN/In _x Ga _1-x N 超晶格 (SL) 的界面极化电场 (IPE)进一步降低热导率 ( k )。由于逆压电效应，IPE 场改变了 SL 的弹性常数和声子速度。由于比热和声子速度的不等变化，这会增强界面散射和热边界电阻，从而导致声子传输减少和声学特性的更多不匹配导致面内 ( k _ip ) 和跨面 ( k _cp ) 热导率降低。室温k _ip在存在（不存在）GaN(10 nm)/In _x Ga _1-x N(5 nm) SL的 IPE 场的情况下，SL 为 7.807(8.921)、7.350(8.355)、7.018(8.090)、8.204(9.402) 和 9.312 (10.564) Wm ^-1 K ^-1分别为x  = 0.1、0.3、0.5、0.7 和 0.9；而对于相同的x，k _cp是 4.652(5.710)、4.282(5.221)、4.081(5.185)、4.871(6.012) 和 6.083(7.327) Wm ^-1 K ^-1表明减少了 20% 以上。它表明可以通过调整氮化物 SL 的电场以获得更好的热电性能来实现所需的k 。