The Sign of Exciton-Photon Coupling in GaN-Based Triangular-like Ridge Cavity

In this paper, the behavior of exciton radiative recombination in a GaN-based triangular-like ridge cavity is studied at room-temperature. The triangular-like ridge cavity is fabricated on a standard-blue-LED epitaxial wafer grown on a sapphire substrate. Through the photoluminescence (PL) and time-resolved photoluminescence (TR-PL) measurements, a clear modulation of the original spontaneous emission is found in the microcavity, a new transition channel is observed, and the effect is angle-dependent. Furthermore, by changing the tilt angle during angle-resolution photoluminescence (AR-PL), it is found that the coupling between excitons and photons in the cavity is the strongest when tilted at 10°. By simulation, the strong localization of photons in the top of the cavity can be confirmed. The PL, TR-PL, and AR-PL results showed the sign of the exciton-photon coupling in the triangular-like ridge cavity.