Scanning tunneling spectroscopy of epitaxial silver indium diselenide

We report on the measurement of the electronic properties of (112) AgInSe2 (AIS) by scanning tunneling microscopy (STM) and spectroscopy (STS). Current-voltage STS measurements show an average band gap of about 1.3 eV and n-type behavior. The IV data also shows band edge fluctuations and a region of states near the valence band edge that decay well into the gap. We compare STS determined band fluctuations in AIS to those previously measured in CuInSe2 (CIS) and find that the fluctuations are smaller in scale in AIS than CIS.