Inverse Photoemission-Studies Of The Si(100)2x1 Surface

A relatively simple and inexpensive inverse photoemission spectrometer with high resolution and high efficiency has been set up. The detector design is of the bandpass type with a novel combination of a CaF 2 window and a channeltron. Gold was selected as the photocathode material and was evaporated onto the inner surface of the channeltron. An inverse photoemission spectrum of the Si(100)2 × 1 surface has been obtained. The spectral resolution is better than 0.5 eV at 9.8 eV photon energy with a counting rate of about 3 × 10 3 /μA · s · sr. The experimental results clearly reveal two peaks associated with empty surface states and, for the first time, assign one of the peaks to antibonding dimer bonds. The data are in good agreement with recent calculations by Krüger.