Biexcitonic contribution to the four-wave-mixing signal from a self-organized quantum-well material (C6H13NH3)2PbI4

Numerous studies have shown that the nonlinear optical responses in quantum-well systems arise primarily from interactions between excitons, and recent investigations have demonstrated that biexcitons play an important role in the nonlinear optical processes. In order to observe biexcitonic effects in quantum-well systems, it is necessary to reduce the inhomogeneous broadening linewidth that originates from the well-width fluctuations. For this reason, observation of biexcitonic effects is limited in high quality crystals. In the present study, we have observed the biexciton contribution to nonlinear optical process in (C₆H₁₃NH₃)₂PbI₄ using four wave mixing (FWM). A FWM experiment was performed using a two-incident-beam configuration