Research Abstract


Extraordinary carrier multiplication gated by a picosecond electric field pulse

2011年12月20日 Nature Communications 2 : 594 doi: 10.1038/ncomms1598


廣理 英基1,2, 篠北 啓介3, 白井 正伸1,2, 谷 峻太郎3, 角屋 豊2,4 & 田中 耕一郎1,2

  1. 京都大学 物質-細胞統合システム拠点
  2. 独立行政法人 科学技術振興機構 戦略的創造研究推進事業
  3. 京都大学 大学院理学研究科 物理学専攻
  4. 広島大学 大学院先端物質科学研究科
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 1MVcm-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.