Electrical characterization of oxygen vacancies in oxides by means of space charge spectroscopy

The development of new materials for cool devices, e.g. memristive and spintronics devices, needs non-destructive techniques to characterize defects in new materials. The knowledge on defects is strongly desired and will help to prevent device degredation. The non-destructive characterization of certain defects is possible by means of positron annihilation spectroscopy (PAS) if open volume-defects are large and electrically neutral/negatively charged, if segregations are attractive for positrons and change the annihilation rate, and/or if the electron density and with that annihilation rate changes during phase transitions. The complementary, destructive characterization of defects in semiconductors prepared as diodes by means of space charge spectroscopy is possible if the defects are charged/decharged in response to electrical pulses applied to the diode.