Optical study of a two-level defect complex in gallium doped ZnO

Abstract

By means of all optical characterizations, carrier dynamics of Ga Zn -V Zn defect complex in Ga doped ZnO film has been systematically studied. It is observed that the defect complex exhibits a red emission centered at 650 nm, different from that of a reference sample containing V O only. From our observations using time-resolved photoluminescence and multiple-wavelength excitation photoluminescence measurements, the energy level of Ga Zn -V Zn is determined to be a two-level system, which is fundamentally different from the reference sample with only a deep level in term of carrier dynamics. This work reveals that Ga Zn -V Zn distinguished from the widely observed V O is a potential candidate for new single photon emitters.

Hot-electron photocurrent detection of near-infrared light based on ZnO

“…33 Obviously, our device is different from UV PDs in both the decay trace and the working mechanism. To explain the decay lifetime, we firstly ruled out the carrier recombination lifetime of 16 ns, 34 and transit time between electrodes (0.38 µs). Moreover, the density of oxygen vacancies of such samples is suppressed as demonstrated in our previous study.…”

“…22 In this work, we attributed it to the defect complex (V Zn − Ga Zn ) −1 near the interface, which is a deep level defect locating 1.085 eV above the valence band maximum. 34 The naturally formed one electron charge (denoted as "−1") will form a local barrier to electrons surrounding the defect (inset of Fig. 4).…”