Tin telluride wavelength range. The alloyed material has been used in mid- IR photodetectors and thermoelectric generator. Tin telluride Tin telluride is a compound of tin and tellurium (SnTe); is a IV-VI narrow band gap semiconductor and has direct band gap of 0.18 eV. It is often alloyed with lead to make lead tin telluride, which is used as an infrared detector material. Tin telluride normally forms p-type semiconductor (Extrinsic semiconductor) due to tin vacancies and is a low temperature superconductor. SnTe exists in 3 crystal phases. At Low temperatures, where the concentration of hole carriers is less than 1.5x10 cm ,
Wedding anniversary for the 50th anniversary, and every fifth anniversary after that. In the United States, a couple can receive a greeting from the President for any wedding anniversary on or after the 50th. Roman Catholics may apply for a Papal blessing through their local diocese for wedding anniversaries of a special nature (25th, 50th, 60th, etc.). The names of some anniversaries provide guidance for appropriate or traditional gifts for the spouses to give each other; if there is a party these can be brought by the guests or influence the theme or decoration. These gifts vary in different countries, but some