Exciton-phonon interaction in the strong-coupling regime in hexagonal boron nitride
Exciton-phonon interaction in the strong-coupling regime in hexagonal boron nitride
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DOI：
10.1103/physrevb.95.201202
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发表时间：
2017-05
影响因子：
3.7
通讯作者：
T. Vuong;G. Cassabois;P. Valvin;S. Liu;J. Edgar;B. Gil
中科院分区：
文献类型：
--
作者：
T. Vuong;G. Cassabois;P. Valvin;S. Liu;J. Edgar;B. Gil
半导体中激子的温度光学响应受激子-声子相互作用的控制。当激子-晶格耦合较弱时，激子线具有由运动窄化引起的洛伦兹轮廓，其宽度随晶格温度T线性增加。相反，当激子-晶格耦合强时，线形状是高斯的，其宽度随着晶格温度亚线性地增加，与sqrt（T）成比例。虽然前一种情况通常在文献中报道，但本文报道的是六方氮化硼。因此，Toyozawa的理论预测[Prog. Theor. 20，53（1958）]通过证明激子-声子相互作用在该货车德瓦耳斯晶体中处于强耦合状态而得到支持。
The temperature-dependent optical response of excitons in semiconductors is controlled by the exciton-phonon interaction. When the exciton-lattice coupling is weak, the excitonic line has a Lorentzian profile resulting from motional narrowing, with a width increasing linearly with the lattice temperature T . In contrast, when the exciton-lattice coupling is strong, the line shape is Gaussian with a width increasing sublinearly with the lattice temperature, proportional to sqrt(T) . While the former case is commonly reported in the literature, here the latter is reported for hexagonal boron nitride. Thus the theoretical predictions of Toyozawa [Prog. Theor. Phys. 20, 53 (1958)] are supported by demonstrating that the exciton-phonon interaction is in the strong-coupling regime in this van der Waals crystal.