Hole mobility of strained GaN from first principles
Hole mobility of strained GaN from first principles
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DOI：
10.1103/physrevb.100.085204
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发表时间：
2019-08
影响因子：
3.7
通讯作者：
S. Ponc'e;D. Jena;F. Giustino
中科院分区：
文献类型：
--
作者：
S. Ponc'e;D. Jena;F. Giustino
氮化物半导体在 LED 和蓝光光盘等光电器件中无处不在。 GaN 在电力电子领域进一步采用的一个主要限制是其空穴迁移率较低。为了应对这一挑战，我们使用从头算的玻尔兹曼输运形式研究了纤锌矿 GaN 的声子限制迁移率，包括所有电子声子散射过程、自旋轨道耦合和多体准粒子能带结构。我们证明了迁移率主要由声变形势散射决定，并且我们预测通过将分裂空穴态提升到轻空穴和重空穴之上可以显着提高空穴迁移率。这可以通过应变反转晶体场分裂的符号或通过超快红外光脉冲相干激发 A$_1$ 光学声子来实现。
Nitride semiconductors are ubiquitous in optoelectronic devices such as LEDs and Blu-Ray optical disks. A major limitation for further adoption of GaN in power electronics is its low hole mobility. In order to address this challenge, here we investigate the phonon-limited mobility of wurtzite GaN using the ab initio Boltzmann transport formalism, including all electron-phonon scattering processes, spin-orbit coupling, and many-body quasiparticle band structures. We demonstrate that the mobility is dominated by acoustic deformation-potential scattering, and we predict that the hole mobility can significantly be increased by lifting the split-off hole states above the light and heavy holes. This can be achieved by reversing the sign of the crystal-field splitting via strain or via coherent excitation the A$_1$ optical phonon through ultrafast infrared optical pulses.