" Quantum Materials is developing QDs with nontoxic zinc or indium cores to replace the cadmium cores used in many QDs (the company also makes high-performance cadmium-based QDs). For its cadmium-core-replacement QDs, Quantum Materials has a philosophy of avoiding the use of rare-earth metals, which are expensive and may sometimes not have an assured supply, and using abundant and nontoxic group II-VI materials."

http://www.laserfocusworld.com/articles/2017/...-show.html