Perovskite materials have the advantages of low cost, simple process and high efficiency, and are commonly used materials for solar panel research. Now, researchers have proved that nanowire laser pointer made from lead halide perovskites are the most efficient lasers known.
Topological image of the nanowire (left insert). At room temperature, two different halide nanowire laser emission images, iodine (red center) and bromine (green on the right) high-efficiency nanowire lasers are beneficial for optical fiber communication, pollution analysis and other applications. The challenge is to find suitable materials. These ultra-compact nanowires have excellent light-emitting ability, adjustable wavelength, and are relatively easy to synthesize. These perovskite-structured nanowires are comparable to high-efficiency solar cell materials.
Semiconductor nanowire lasers, due to their ultra-compact physical structure, high coherent output and high efficiency, are the preferred components for integrating nano-level photonics and optoelectronic devices. Moreover, only a small threshold is required for excitation, and only a small amount of light is emitted below the threshold.
In nanowire blue laser pointer technology, the high “laser threshold” not only makes it difficult to advance key technologies, but also limits the laser performance and causes other energy losses. In order to find ideal nanowire laser materials, researchers at Columbia University and the University of Wisconsin-Madison have studied a new material, methylammonium lead halide perovskite (CH3NH3PbX3), which is an emerging high-efficiency solar cell The main material has low cost, simple process and high efficiency.
The outstanding performance of lead halide perovskite in solar cells is attributed to its long carrier lifetime and low non-radiative recombination rate, which are also ideal characteristics for preparing semiconductor lasers. At room temperature, these nanowire lasers have the lowest laser threshold and nearly 100% laser efficiency (the ratio of the number of photons emitted and absorbed, and each photon absorbed can release a laser photon), and the laser wavelength adjustable range covers Features from near infrared to visible light.
Specifically, the laser emission from near infrared to blue light is caused by the reduction of the atomic number of the halide (X = I, Br, Cl) on the nanowire. These nanowires can promote the application of nanophotonics and optoelectronic devices. Especially the laser in the near-infrared region can be better applied to optical fiber communication.