: Hyungrae Cha, Seunghwan Bae, Hyunho Jung, Min Jae Ko, and Heonsu Jeon

: Adv. Opt. Mater. 5(22), 1700545 (2017)

We report single-mode laser operation from a solution-processed halide perovskite alloy system, CH(NH2)2Pb(I1–xBrx)3 (0 ≤ x ≤ 1). Despite its simplicity, the solution process results in halide perovskite alloy films of smooth and uniform surface morphology that exhibit characteristics of bandgap engineering, where the bandgap and thus emission wavelength can be tuned (from near-infrared to green) by controlling the anion composition ratio x. A set of thin films of the halide perovskite alloy are coated on top of the fused quartz substrates with engraved surface gratings and are optically excited to induce distributed feedback lasing action. Laser devices operate in single modes over a wide range of wavelengths, depending on the composition ratio, up to room temperature for x = 0 and 1 and up to 200 K for alloys. We also demonstrate control of the polarization of the single-mode laser output by carefully choosing the grating period. Our achievement is an important milestone towards the advancement in the applicability of halide perovskite materials to optoelectronic devices. DOI: 10.1002/adom.201700545