Local levels in La1-xSrxScO3-x/2 band-gap under interaction with components of O2, H2, H2O atmospheres

With increasing in dopant concentration x the absorption band at 5.6 eV overlapping with the edge of fundamental absorption increases. Most probably it can be related with oxygen vacancies. When protons are incorporated from the H2 atmosphere into the La1-xSrxScO3-x/2 lattice, the absorption intensity in this band decreases, which can be due to the transition of the defects causing this band to another charge state. In addition, specific defects that absorb in the red and IR region at hν < 2.2 eV are formed. They are found to be located deep enough in the bang-gap and not to be an electronic traps. It is also shown that in La1-xSrxScO3-x/2 there are electron traps located at a depth of 2-4.5 eV in the band-gap relative to the bottom of the conduction band. On the basis of the obtained data, it can be assumed that these defects are somehow associated with oxygen vacancies, but their charge state is not obvious. It is important that these traps participate in the capture of uncompensated electrons during the proton uptake from the H2 atmosphere.