Chances are, you’ve heard of Selenium. As a trace element, it is an essential mineral found in small amounts in the body, with antioxidant properties. It is also a much-used suite of tools to automate web browsers across many platforms — which is why weeding out our news alerts for stories relevant to ARPN followers can be time-consuming.
However, more relevant from our vantage point are this rare mineral’s other uses. According to USGS, Selenium, which is known to have semiconducting properties, is used in glass manufacturing to decolorize the green tint caused by iron impurities, and — increasingly important to new applications — to reduce solar heat transmission. In catalysts, it enhances selective oxidation, in plating solutions, it improves appearance and durability, and in gun bluing, it improves appearance and provides corrosion resistance. It is further used in rubber-compounding chemicals, in the electrolytic production of manganese, and in copper, lead, and steel alloys to improve machinability.
Perhaps its most important use today is its application in solar technology. Like Tellurium, Selenium plays a critical role in the performance of thin-film photovoltaic cells. While Tellurium is used in combination with Cadmium for CdTe technology, Selenium is alloyed with Copper, Indium and Gallium, creating a material commonly referred to as CIGS.
Both CdTe and CIGS technologies were the new kids on the block during the first solar boom, though Selenium’s photoconductive properties were already discovered by British scientist Willoughby Smith in 1873. Companies engaged in both technologies have since vied for front-runner status in the solar world by attempting to improve the respective material’s efficiencies. While CIGS seemed to have a leg up up until recently, new test results for CdTe are promising. The bottom line, however: both materials, and with that Tellurium and Selenium, are in high demand.
What holds true for most tech metals and minerals, applies here too: substitution may occur, but technological advances in materials sciences will likely continue to fuel demand. Selenium may have been replaced by organic photoreceptors in some plain paper copiers, but new nano-technological applications, for example in electronics, are already being tested by researchers.
As is the case with Tellurium, most Selenium used in the United States is derived from residues produced during the refining process of Copper, so the supply of Selenium is of course directly affected by the supply of Copper.
If you’ve read our last post about Tellurium, you probably have Bob Marley’s “No Woman, No Cry” stuck in your head now. You’re welcome.