Indium phosphide (InP) is a binary semiconductor composed of indium and phosphorus. Commercially significant products include gallium phosphide and indium phosphide. Germanium or Indium gallium arsenide (InGaAs) detectors are commonly used. Copper indium gallium selenide is a material used in solar cells. One proposed material is indium gallium arsenide, or InGaAs. The primary photodetectors for telecommunications are made from Indium gallium arsenide. It forms well-defined intermetallic compounds with antimony, gallium, indium, and thorium, which are photosensitive. Blue gold is an alloy of gold and either gallium or indium. Aluminium from group 13 forms carbides, but gallium, indium, and thallium do not. Antimony forms antimonides with metals, such as indium antimonide (InSb) and silver antimonide (). Secondary products include lead, silver, gold, molybdenum, germanium, indium and cadmium. These include phosphorus, antimony, zinc, tin, lead, indium, silver, gold and copper. Flat panel displays incorporate a thin film of electrically conducting indium tin oxide. Other metals included in gold alloys are copper, platinum, palladium, zinc, indium and nickel. The dispersed spectrum of light was focused on detectors of indium, antimonide and silicon.