, M is a metal or chalcogenide element and x has the value 2-15, as well as a method of optically...http://www.google.com/patents/US4818666?utm_source=gb-gplus-sharePatent US4818666 - Composed of antimony, gallium or indium, and metal or chalcogenideAdvanced Patent SearchPublication numberUS4818666 APublication typeGrantApplication numberUS 06/869,484Publication dateApr 4, 1989Filing dateJun 2, 19