InGaN-Based Quantum Well Superluminescent Diode Monolithically Grown on Si

Monolithic integration of an InGaN-based superluminescent diode (SLD) on a Si platform permits the fabrication of a cost-effective, compact, broadband, and low-delay light source for a speckle-free display and visible-light communications (VLC). Here, we report the first demonstration of an InGaN-based multiple quantum wells SLD monolithically grown on Si substrates. The as-fabricated SLD produces a close-to-Gaussian electroluminescence spectrum centered at 410 nm, with a broad spectral bandwidth of 3.6 nm (26 meV) at room temperature. The SLD is linearly TE polarized with a degree of polarization as large as 98% when the current increased to 600 mA, which corresponds to a polarization extinction ratio of 20 dB. Such results confirm the stimulated amplification when the diode operates in the superluminescence mode. Furthermore, the SLDs exhibit a low RC delay of 1.77 GHz, suggesting highly promising applications in high-speed transmitter for VLC. This work paves the way for monolithic integration of III nitride on-chip light sources on a Si platform.