Zimmermann, ChristianFrodason, Ymir KalmannBarnard, Abraham WillemVarley, Joel BasileIrmscher, KlausGalazka, ZbigniewKarjalainen, AnttiMeyer, Walter ErnstAuret, Francois DanieVines, Lasse2020-09-302020-09-302020-02-18Zimmermann, C., Frodason, Y.K., Barnard, A.W. et al. Ti- and Fe-related charge transition levels in beta-Ga2O3. Applied Physics Letters 116, 072101 (2020); https://DOI.org/10.1063/1.5139402.0003-6951 (print)1077-3118 (online)10.1063/1.5139402http://hdl.handle.net/2263/76276Deep-level transient spectroscopy measurements on b-Ga2O3 crystals reveal the presence of three defect signatures labeled E2a; E2b, and E3 with activation energies at around 0.66 eV, 0.73 eV, and 0.95 eV below the conduction band edge. Using secondary ion mass spectrometry, a correlation between the defect concentration associated with E3 and the Ti concentration present in the samples was found. Particularly, it is found that E3 is the dominant Ti-related defect in b-Ga2O3 and is associated with a single Ti atom. This finding is further corroborated by hybrid functional calculations that predict Ti substituting on an octahedral Ga site, denoted as TiGaII, to be a good candidate for E3. Moreover, the deep level transient spectroscopy results show that the level previously labeled E2 and attributed to Fe substituting on a gallium site (FeGa) consists of two overlapping signatures labeled E2a and E2b. We tentatively assign E2a and E2b to Fe substituting for Ga on a tetrahedral or an octahedral site, respectively.en© 2020 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.Ti concentrationE3Ti substitutingTi atomDeep-level transient spectroscopy (DLTS)Beta-Ga2O3Article