title: Extraordinary carrier multiplication gated by a picosecond electric field pulse.
abstract: The study of carrier multiplication has become an essential part of many-body physics and materials science as this multiplication directly affects nonlinear transport phenomena, and has a key role in designing efficient solar cells and electroluminescent emitters and highly sensitive photon detectors. Here we show that a 1-MVcm(-1) electric field of a terahertz pulse, unlike a DC bias, can generate a substantial number of electron-hole pairs, forming excitons that emit near-infrared luminescence. The bright luminescence associated with carrier multiplication suggests that carriers coherently driven by a strong electric field can efficiently gain enough kinetic energy to induce a series of impact ionizations that can increase the number of carriers by about three orders of magnitude on the picosecond time scale.
authors.affiliation: Institute for Integrated Cell-Material Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan. hirori@icems.kyoto-u.ac.jp
authors.forename: H
authors.initials: H
authors.lastname: Hirori
authors.forename: K
authors.initials: K
authors.lastname: Shinokita
authors.forename: M
authors.initials: M
authors.lastname: Shirai
authors.forename: S
authors.initials: S
authors.lastname: Tani
authors.forename: Y
authors.initials: Y
authors.lastname: Kadoya
authors.forename: K
authors.initials: K
authors.lastname: Tanaka
mesh_terms: D004560:Electricity; D004581:Electronics / Q000295:instrumentation / Q000379:methods*; D004583:Electrons; D007259:Infrared Rays; D049449:Luminescence; D055096:Optical Devices; D017785:Photons; D055053:Terahertz Radiation; D013816:Thermodynamics