Solution-processed PbS quantum dot infrared laser with room-temperature tuneable emission in the optical...

Solution processed semiconductor lasers have achieved much success across the nanomaterial research community, including in organic semiconductors^1,2, perovskites^3,4 and colloidal semiconductor nanocrystals^5,6. The ease of integration with other photonic components, and the potential for upscaling using emerging large area fabrication technologies, such as roll-to-roll⁷, make these lasers attractive as low-cost photonic light sources that can find use in a variety of applications: integrated photonic circuitry^8,9, telecommunications^10,11, chemo-/bio-sensing^12,13, security¹⁴, and lab-on-chip experiments¹⁵. However, for fiber-optic or free-space optical (FPO) communications and eye-safe LIDAR applications, room temperature solution-processed lasers have remained elusive. Here we report the first solution processed laser, comprising PbS colloidal quantum dots (CQDs) integrated on a distributed feedback (DFB) cavitiy, with tuneable lasing wavelength from 1.55 microm - 1.65 microm. These lasers operate at room temperature and exhibit linewidths as low as ~0.9 meV.