Dominant defects and carrier transport in single crystalline cuprous oxide: A new attribution of optical transitions

Abstract

Electronic properties of single crystal (111) Cu2O wafers have been investigated using a number of complementary techniques. Secondary ion mass spectrometry has shown significant presence of hydrogen and nitrogen. Cathodoluminescence measurements reveal strong near-band emission indicating the good electronic quality of the wafers. Two deep emission lines are observed at 1.3 and 1.7 eV. Temperature-dependent Hall effect measurements reveal electronic levels at around EV + 0.16 eV, EV + 0.22 eV, and ∼EV + 0.4 eV, where EV is the valence band edge. The discussion on the identity of the electronic centers calls for a revision of the traditional assignments of the 1.3-eV and 1.7-eV lines in order to take into account independent theoretical predictions. The temperature dependence of carrier mobility shows that the mechanism limiting the mobility can be described by scattering on neutral and ionized defect centers.