Four elements make 2-D optical platform

The Rice lab of materials scientist Pulickel Ajayan grew

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the four-component alloy of transition metals molybdenum and tungsten with chalcogens sulfur and selenium in a chemical vapor deposition furnace. They found changes in temperature made subtle changes in the way atoms assembled and also altered the properties that determine how they absorb and emit light.

Their experiments were built upon work by the lab of Rice theoretical physicist Boris Yakobson, which created scores of models to predict how various combinations of the four elements should work.

The process should be of interest to engineers looking to make smaller, more-efficient devices. Because the bandgap falls in the optical range of the electromagnetic spectrum, the researchers said solar cells and light-emitting diodes might be the first beneficiaries.

The paper appears as a cover story in the current issue of Advanced Materials.

The team led by co-lead author and Rice research scientist Alex Kutana generated 152 random models of the material that showed the bandgap could be tuned from 1.62 to 1.84 electron volts by varying the growth temperature from 650 and 800 degrees Celsius (1,202 to 1,472 degrees Fahrenheit).

Read more at: https://phys.org/news/2017-09-elements-d-optical-platform.html#jCp