High Quality Content by WIKIPEDIA articles! Copper zinc tin sulfide (CZTS) is a quaternary semiconducting compound which has received increasing interest since the late 2000’s for applications in solar cells. The class of related materials includes other I2-II-IV-VI4 such as copper zinc tin selenide (CZTSe) and the sulfur-selenium alloy CZTSSe. CZTS offers favorable optical and electronic properties similar to CIGS (copper indium gallium selenide) making it well suited for use as a thin film solar cell absorber layer, but unlike CIGS (or other thin films such as CdTe), CZTS is composed of only abundant and non-toxic elements. Concerns with the price and availability of indium in CIGS and tellurium in CdTe, as well as toxicity of cadmium have been a large motivator to search for alternative thin film solar cell materials. Recent material improvements for CZTS have increased efficiency to just above 10% in laboratory cells, but more work will be needed for successful commercialization .