Direct determination of graphene quantum dots based on terbium-sensitized luminescence.

See more Terbium products. Terbium (atomic symbol: Tb, atomic number: 65) is a Block F, Group 3, Period 6 element with an atomic radius of 158.92535. The number of electrons in each of Terbium's shells is [2, 8, 18, 27, 8, 2] and its electron configuration is [Xe]4f⁹ 6s². The terbium atom has a radius of 177 pm and a Van der Waals radius of 221 pm.Terbium was discovered and first isolated by Carl Gustaf Mosander in 1842. In its elemental form, terbium is a silvery-white soft metal. Terbium is found in cerite, gadolinite, and monazite. It is not found in nature as a free element. Terbium compounds are brightly fluorescent, and a majority of the world's terbium supply is used for creating green phosphors that enable trichromatic lighting technology. It is also frequently used as a dopant for crystalline solid-state devices and fuel cell materials. It is named after Ytterby, the town in Sweden where it was discovered.

See more Carbon products. Carbon (atomic symbol: C, atomic number: 6) is a Block P, Group 14, Period 2 element. The number of electrons in each of Carbon's shells is 2, 4 and its electron configuration is [He]2s² 2p². In its elemental form, carbon can take various physical forms (known as allotropes) based on the type of bonds between carbon atoms; the most well known allotropes are diamond, graphite, amorphous carbon, glassy carbon, and nanostructured forms such as carbon nanotubes, fullerenes, and nanofibers . Carbon is at the same time one of the softest (as graphite) and hardest (as diamond) materials found in nature. It is the 15th most abundant element in the Earth's crust, and the fourth most abundant element (by mass) in the universe after hydrogen, helium, and oxygen. Carbon was discovered by the Egyptians and Sumerians circa 3750 BC. It was first recognized as an element by Antoine Lavoisier in 1789.