Abstract
Electron-phonon (El-Ph) coupling is a fundamental physical process in solids. It is also widely involved in photoluminescence process in solids, leading to so-called phonon-assisted optical spectra. El-Ph coupling process and principle have been extensively investigated both theoretically and experimentally since 1950’s. For phonon-assisted optical spectra in solids, a big progress was widely credited to Huang and Rhys [1] who developed the first quantum mechanical theory. After Huang-Rhys’s work, a key physical quantity, namely Huang-Rhys factor, has been generally recognized and adopted to characterize El-Ph coupling strength. In this work, we use another algebraic method developed by O’Rourke [2] to derive a formula which can be applied in more general situations and will be coincident with the Huang-Rhys’s equation when all phonons have the same frequency. Then, we calculate phonon-assisted photoluminescence spectra for different Huang-Rhys factors and temperatures, and compare with the experimental data of GaN crystal.
[1] K. Huang, and A. Rhys, Proc. Roy. Soc. (London) A204, 406 (1950).
[2] R. C. O’Rourke, Phys. Rev. 91, 265 (1953).
Anyone interested is welcome to attend.