Cesium is a Block S, Group 1, Period 6 element. The electronic configuration is [Xe] 6s¹. In its elemental form cesium's CAS number is 7440-46-2. The cesium atom has a radius of 265.5.pm and it's Van der Waals radius is 200.pm. Cesium is a member of the alkali group of metals. It is one of three metals that occur as a liquid at room temperature - the others are mercury and gallium. Cesium is available as metal and compounds with purities from 99% to 99.999% (ACS grade to ultra-high purity); metals in the form of foil, sputtering target, and rod, and compounds as submicron and nanopowder. Cesium is used as an oxygen "getter" in vacuum and electronic tubes and as a component of photoelectric cells.

Selenium is a Block P, Group 16, Period 4 element. The electronic configuration is [Ar] 3d¹⁰ 4s² 4p⁴. In its elemental form selenium's CAS number is 7782-49-2. The selenium atom has a radius of 116.pm and it's Van der Waals radius is 190.pm. Selenium exhibits both photovoltaic action, where light is converted directly into electricity, and photoconductive action, where the electrical resistance decreases with increased illumination. These properties make selenium useful in the production of photocells and exposure meters for photographic use, as well as solar cells. Below its melting point, selenium is a p-type semiconductor and has many uses in electronic and solid-state applications. Selenium is available as metal and compounds with purities from 99% to 99.9999% (ACS grade to ultra-high purity); metals in the form of foil, sputtering target, and rod, and compounds as submicron and nanopowder. Selenium was first discovered by Jons Berzelius in 1817.

American Elements semi conducting materials are crystal structures produced from ultra high purity starting materials synthesized by our high purity production facility which includes several large electric muffle furnaces, a tube furnace for hydrogen reduction, 50 gallon glass-lined Pfaudler reactors supported by our analytical laboratory containing X-ray diffraction, SEM, AA, BET surface area, and ICP Spectrometry for trace metals analysis. See a discussion of American Elements Ultra High Purity and Analytical capabilities. See Crystal Growth for processes used to fabricate semiconductor materials, which include: