  Coherent light sources in silicon photonics are the long-sought holy grail
because silicon-based materials have indirect bandgap. Traditional strategies
for realizing such sources, e.g., heterogeneous photonic integration, strain
engineering and nonlinear process, are technologically demanding. Here, we
demonstrate a hybrid lasing device composing of perovskite nanocrystals and
silicon nitride nanobeam cavity. We fabricate SiN photonic crystal naonobeam
cavities on a solid substrate with significantly improved thermal and
mechanical stabilities compared to conventional suspended ones. In addition,
adding a PMMA-encapsulation layer on top of the SiN can significantly boost the
Q-factor of the cavity mode. By dispersing perovskite nanocrystals as emitters
in the PMMA layer, we obtained high-performance coherent emissions in terms of
lasing threshold, linewidth and mode volumes. Our work offers a compelling way
of creating solution-processed active integrated photonic devices based on the
mature platform of silicon photonics for applications in optical information
science and photonic quantum technology.
