Nanolaser Using Colloidal Quantum Wells Deterministically Integrated on a Nanocavity

Abstract

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 onchip light sources. Additionally, we show that the shelling of the colloidal quantum wells is essential for maximizing gain.