title: Graphene, a material for high temperature devices--intrinsic carrier density, carrier drift velocity, and lattice energy.
abstract: Heat has always been a killing matter for traditional semiconductor machines. The underlining physical reason is that the intrinsic carrier density of a device made from a traditional semiconductor material increases very fast with a rising temperature. Once reaching a temperature, the density surpasses the chemical doping or gating effect, any p-n junction or transistor made from the semiconductor will fail to function. Here, we measure the intrinsic Fermi level (|EF| = 2.93 kBT) or intrinsic carrier density (nin = 3.87 × 10(6) cm(-2)K(-2)· T(2)), carrier drift velocity, and G mode phonon energy of graphene devices and their temperature dependencies up to 2400 K. Our results show intrinsic carrier density of graphene is an order of magnitude less sensitive to temperature than those of Si or Ge, and reveal the great potentials of graphene as a material for high temperature devices. We also observe a linear decline of saturation drift velocity with increasing temperature, and identify the temperature coefficients of the intrinsic G mode phonon energy. Above knowledge is vital in understanding the physical phenomena of graphene under high power or high temperature.
authors.affiliation: The Institute of Physics, Chinese Academy of Sciences, Beijing 100190, P. R. China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Yin
authors.affiliation: National Center for Nanoscience and Technology, Beijing 100190, P. R. China.
authors.forename: Zengguang
authors.initials: Z
authors.lastname: Cheng
authors.affiliation: The Institute of Physics, Chinese Academy of Sciences, Beijing 100190, P. R. China.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.affiliation: The Institute of Physics, Chinese Academy of Sciences, Beijing 100190, P. R. China.
authors.forename: Kuijuan
authors.initials: K
authors.lastname: Jin
authors.affiliation: Minzu University of China, Beijing 100081, P. R. China.
authors.forename: Wenzhong
authors.initials: W
authors.lastname: Wang