K. Sauthoff

Publications (3)10.63 Total impact

• Article: Optical detection of ballistic electrons injected by a scanning-tunneling microscope.

  M Kemerink, K Sauthoff, P M Koenraad, J W Gerritsen, H van Kempen, J H Wolter
  [show abstract] [hide abstract]
  ABSTRACT: We demonstrate a spectroscopic technique which is based on ballistic injection of minority carriers from the tip of a scanning-tunneling microscope into a semiconductor heterostructure. By analyzing the resulting electroluminescence spectrum as a function of tip-sample bias, both the injection barrier height and the carrier scattering rate in the semiconductor can be determined. This technique is complementary to ballistic electron emission spectroscopy since minority instead of majority carriers are injected, which give the opportunity to study the carrier trajectory after injection.
  Physical Review Letters 04/2001; 86(11):2404-7. · 7.37 Impact Factor
• Article: Optical properties of a tip-induced quantum dot

  M. Kemerink, K. Sauthoff, P.M. Koenraad, J.W. Gerritsen, H. van Kempen, V.M. Fomin, J.H. Wolter, J.T. Devreese
  [show abstract] [hide abstract]
  ABSTRACT: We have performed optical spectroscopy measurements on a STM-tip-induced quantum dot in a GaAs layer. The dominant confinement in the (hole) quantum dot is found to be in the direction parallel to the tip axis. Electron confinement is achieved by a sub-surface AlGaAs barrier. Current-dependent measurements indicate that many-body interactions can cause spectral blueshifts up to 75 meV for a tunneling current of 10 nA. Consequently, a full treatment of the many-body problem is required for an accurate description of this type of system.
  Applied Physics A 03/2001; 72(8):S239-S242. · 1.63 Impact Factor
• Article: Optical detection of ballistically injected electrons in III/V heterostructures

  M. Kemerink, K. Sauthoff, P.M. Koenraad, J.W. Gerritsen, H. van Kempen, J.H. Wolter
  [show abstract] [hide abstract]
  ABSTRACT: We present a novel spectroscopic technique that is based on the ballistic injection of minority carriers from the tip of a scanning-tunneling microscope into a semiconductor heterostructure. By analyzing the resulting electro-luminescence spectrum as a function of tip-sample bias, both the injection barrier height and the carrier relaxation rate &#38s after injection can be determined. At 4.2 K we found &#38s=5ꔕ s-1 and at 77 K we found &#38s=8ꔕ s-1. From current-dependent measurements we find that, at room temperature, a large fraction of the carriers is trapped prior to radiative recombination. At high currents or low temperatures the traps become saturated. We tentatively identify the Be acceptors in the structure as trapping centers.
  Applied Physics A 03/2001; 72(8):S201-S204. · 1.63 Impact Factor