Enhanced indirect-to-direct inter-valley scattering in germanium under tensile strain for improving the population of electrons in direct valley. (23rd October 2018)

• Record Type: Journal Article
• Authors: Huang, Shi-Hao; Zheng, Qi-Qiang; Xie, Wen-Ming; Lin, Jin-Yang; Huang, Wei; Li, Cheng; Qi, Dong-Feng
• Is Part Of: Journal of physics. Volume 30:Number 46(2018)
• Publication Date: 2018-10-23
• Subjects: strained germanium -- inter-valley scattering -- phonon engineering -- electron transferring model; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/1361-648X/aae50e
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: A theoretical model is proposed to analyze the inter-valley electron transferring between direct Γ and indirect L valleys, which sheds light on the electron conduction dynamics in (0 0 1) tensile strained Ge. Inter-valley scattering is included to calculate average scattering time between Γ and L valleys based on a time-dependent Hamiltonian describing the electron–phonon interaction. Numerical results indicate that enhanced indirect-to-direct inter-valley scattering and reduced direct-to-indirect inter-valley scattering are reliable by introducing tensile strain in Ge material. The population ratio of electrons in Γ and L valleys in strained Ge will increase one to two orders of magnitude compared to the model without the inter-valley scattering. The results offer fundamental understanding of phonon engineering for further improvement of performance in strained germanium light sources.