The picture on the left shows high purity (99.999%) pellets of copper (red), indium (silver), and selenium (black) in a quartz tube in the atomic proportions of 1:1:2 respectively. This is in preparation for the synthesis of these three elements in to the compound CuInSe₂ by sealing the tube into a closed ampoule, heating and allowing chemical reaction to take place. With the compound at a temperature above its melting point, the liquid is allowed to freeze from one end by slowly lowering the sealed ampoule through a steep temperature gradient. As a result of this process, called the Bridgman method, a solid ingot of CuInSe₂ is obtained, containing large single crystals, which can be studied physically on account of their interesting semiconducting properties.

The picture on the right shows triangular facets on a face of a single crystal of the semiconducting compound CuInSe₂, as observed under an optical microscope after growth of the material from the liquid state (using a process called the Bridgman method). The facets are terraces of growth steps and their triangular shapes and 60^o angles indicate that the surfaces are (112) crystallographic planes, which have a 3-fold symmetry in a chalcopyrite structure. Similar triangular pattersn, called etch pits, can be obtained on a (112) face of a crystal of CuInSe₂ by etching chemically with an acid or thermally by heating above 600^oC in a vacuum. Compounds basedon this material have potential in thin film photovoltaic solar cells, arising from their high absorption of light in a range of wavelengths where the sun has its greatest intensity.