Temperature-dependent trion-induced tunability of the terahertz signal response enabled by intraband transitions in monolayer WS2

Abstract

Recently, the unexplored interaction of thermally excited trions with THz radiation has attracted significant attention in the design of highly-efficient communication devices. It is a challenge to investigate thermally excited trions present in monolayer two dimensional materials to push towards quantum limits in the terahertz regime. Herein, this is explored by presenting a comprehensive conceptual framework, employing temperature dependent time domain terahertz spectroscopy to elucidate the tunability of the terahertz signal response induced by trions through intraband transitions in monolayer WS₂. Delving deeper into the structural nuances, photoluminescence peaks have been de-convoluted to discern the energies corresponding to excitonic and trionic contributions. A good agreement is found between experimental data and existing theoretical concepts of thermally excited trions. Hence, this method stands as a paramount tool in probing the quantum behaviour of trions, given the seamless alignment with the intraband gap through terahertz radiation energy, to design next-generation wireless communication devices.