Deep-blue DBR laser at room temperature from single-crystalline perovskite thin film

Organic-inorganic hybrid perovskite semiconductors as gain materials have been widely investigated in various lasing structures. Here, we construct a vertical cavity surface-emitting deep-blue laser device in one step. A high-quality CH3NH3PbCl3 single-crystalline film as gain material is in situ grown in solution confined between a pair of distributed Bragg reflectors, which naturally form an optical microcavity. The thickness of the perovskite film can be easily adjusted from submicron to several microns by changing the applied pressure on the substrates. At room temperature, the resulting device can lase in a range of 414–435 nm when pumped by an 8 ns pulsed semiconductor laser diode, exhibiting a typical threshold of 211 μJ/cm2. The lasing wavelength and the number of modes are tunable due to the adjustable thickness of the perovskite film.