Exciton-plasmon polariton coupling and hot carrier generation in two-dimensional SiB semiconductors: a first-principles study

Exciton (strong electron-hole interactions) and hot carriers (HCs) assisted by surface plasmon polaritons show promise to enhance the photoresponse of nanoelectronic and optoelectronic devices. In the current research, we develop a computational quantum framework to study the effect of coupled exciton and HCs on the photovoltaic energy distribution, scattering process, polarizability, and light emission of two-dimensional (2D) semiconductors. Using a stable 2D semiconductor (semihydrogenated SiB) as our example, we theoretically show that external strain and thermal effect on the SiB can lead to valley polarized plasmon quasiparticles and HC generation. Our results reveal that the electron-phonon and electron-electron (e-e) interactions characterize the correlation between the decay rate, scattering of excitons, and generation of HCs in 2D semiconductors. Moreover, phonon assisted luminescence spectra of SiB suggest that light emission can be enhanced by increasing strain and temperature. The polarized plasmon with strong coupling of electronic and photonics states in SiB makes it as a promising candidate for light harvesting, plasmonic photocurrent devices, and quantum information.