Nanolaser Using Colloidal Quantum Wells Deterministically Integrated on a Nanocavity

On-chip light sources based on hybrid integration of colloidal semiconductor nanocrystal emitters with integrated photonics have focused on either colloidal emitters ill-suited to act as gain media due to large Auger recombination or nonscalable suspended nanocavity geometries with a randomly positioned colloidal gain material. In this work, we demonstrate a nanolaser by integrating colloidal quantum wells with an on-substrate nanobeam cavity geometry. We employ deterministic positioning of colloidal quantum wells to enhance the coupling of the gain material to the cavity. This device achieves lasing under continuous-wave optical pumping at room temperature with a threshold of 2.9 μW, which demonstrates the suitability of this hybrid platform for scalable on-chip light sources. Additionally, we show that the shelling of the colloidal quantum wells is essential for maximizing gain.