New Method of Nanowire and Laser Fabrication

Researchers at Berkeley National Laboratory reported that they have found a new way to make nanoscale wires and color tunable nanoscale laser generators. With a minimum diameter of 200 nanometers and a wide range of other materials, these wires deliver a bright and stable laser that is expected to find applications in optoelectronics and data transmission. The study was moderated by Lawrence Berkeley National Laboratory researcher and professor of chemistry at the University of California, Berkeley, Yang Pei-Dong. With a simple chemical impregnation solvent process, researchers "self-assemble" materials into nanocrystals, sheets and wires. In a paper published in the Proceedings of the National Academy of Sciences of the United States, the researchers said that they dipped a leaded film into a methanol solvent containing cesium, bromine, and chlorine and heated the solvent to 50 degrees Celsius. The resulting cesium, lead, and bromine The crystal structure of wire diameter of 200 nm to 2300 nm, length of 2 microns to 40 microns. Yang Peidong said: "Surprisingly, the chemical process is very simple." In contrast, if the standard process for the production of nano-wire, require expensive instruments and high temperature and other harsh conditions, the effect is not necessarily ideal. In laser experiments, the nanowires act as a laser generator on a quartz substrate and emit light when excited by another laser generator. The researchers confirmed that nanoscale laser generators emit more than 1 billion cycles of light after being pulsed with visible violet laser pulses that have a very short duration of only a single pulse (only one billionth of a second in 1 second) Extremely stable performance. According to Yang Pei-Dong, this is based on what he knows is by far the first nanoscale laser generator made entirely of inorganic materials, ie, carbon-free materials. Experiments show that the light emitted by this laser can be tuned within a certain range, including visible green and blue bands. Using a fluoroscopy, researchers found that the crystal structure of nanowires resembles naturally occurring perovskites, similar to salt, and susceptible to moisture in the air. In response to this flaw, Yang Peidong envisions the possibility of coating nanowires with polymers or other materials to protect them from erosion. The new nanomaterials used in nanoscale laser generators have also shown promising applications in the development of next generation high efficiency solar cells. Yang Peidong said that the creation of nano-laser generator is expected to open up a new frontier applications for these materials.