Deep level transient spectroscopy analysis of an anatase epitaxial film grown by metal organic chemical vapor deposition

The deep level transient spectroscopy (DLTS) study of anatase-type TiO2 material was performed for the first time. The anatase film was epitaxialy grown on a conductive Nb-doped single-crystalline SrTiO3 (100) substrate by metal organic chemical vapor deposition. The photoluminescence characteristics of this anatase film were identical to those in previous reports, where they were attributed to the radiative recombination of self-trapped excitons. According to the DLTS analysis, it was revealed that this anatase film had a characteristic deep level located at 0.96 eV below the bottom of the conduction band with large concentration (6.5 x 10(16)/cm(3)) and capture cross section (8.3 x 10(-13) cm(2)). Since the capture cross section of this level appeared to be too large to be caused by point defects. the origin of this deep level was attributed to line defects such as dislocations.