GT Advanced Technologies Inc. provides polysilicon production technology and crystalline ingot growth systems, and related photovoltaic (PV) manufacturing services for the solar industry worldwide. It also offers sapphire growth systems and material for the light emitting diode (LED) and other specialty markets. The company’s principal products comprise silicon deposition reactors and related equipment, which are used to produce polysilicon for applications in silicon-based solar wafers and cells; directional solidification (DSS) furnaces and related equipment used to cast multicrystalline and MonoCast crystalline silicon ingots, which are used to make PV solar wafers and cells; and sapphire crystallization furnaces, which are used to crystallize sapphire boules for use in the manufacture of LED devices. In addition, it provides equipment, technology, and engineering services for the production and purification of trichlorosilane and silane; and engineering services for the commissioning, start-up, and optimization of its polysilicon equipment and technology, as well as hydrochlorination technology that eliminates the need for silicon tetrachloride converters in polysilicon production. Further, the company sells replacement parts and consumables used in its DSS furnaces and other PV equipment. GT Advanced Technologies Inc. sells its equipment and services to polysilicon producers, solar wafer manufacturers, and sapphire producers through direct sales force and indirect sales representatives. The company was formerly known as GT Solar International, Inc. and changed its name to GT Advanced Technologies Inc. in August 2011. GT Advanced Technologies Inc. was founded in 1994 and is headquartered in Merrimack, New Hampshire.